賈工 先楫資深 FAE

12年產品研發(fā)經驗，具有變頻器、伺服等工業(yè)產品開發(fā)經驗，也負責過激光投影顯示系統(tǒng)開發(fā)、AI應用開發(fā)、PYQT、Linux驅動開發(fā)等工作。

1、SEI簡介

SEI（Serial Encoder Interface）串行編碼器接口，是先楫半導體創(chuàng)新性設計的一個針對串行絕對值編碼器通信的外設。SEI支持同步通信模式與異步通信模式，既能做主機——從編碼器獲取數據，又能做從機——將位置信息以主機需要的串行協議發(fā)出。在電機類應用中極大的降低了編碼器相關開發(fā)任務的難度，同時以硬件編解碼的方式降低了CPU負載率，讓CPU有更多算力處理其他任務。

先楫半導體SDK 1.5.0提供了諸多SEI應用的實例，包括BISS-C、Endat、Hiperface、Nikon、SSI、Tamagawa等串行協議的主站、從站配置源碼，開發(fā)者在sample實例的基礎上，簡單的進行修改即可應用到項目中。

本文以Tamagawa協議為例，對SEI在異步通信中用法進行講解，同時對slave例程進行修改，增加對Tamagawa協議中EEPROM指令的支持，使讀者對SEI的用法有進一步的認識與了解。

本文中，命令指協議中主站向從站發(fā)送的命令，從站需要根據命令內容進行回復或執(zhí)行某些操作；指令指SEI引擎執(zhí)行的動作。

1.1SEI關鍵概念

1.1.1數據寄存器

數據寄存器是SEI收發(fā)數據的數據存放單元。在通信的接收過程中，接收到的數據會被存放于數據寄存器中；在通信的發(fā)送過程中，需要向外發(fā)送的數據同樣存放在數據寄存器中。

SEI共有9組數據寄存器，每個寄存器寬度為32bit。當以字節(jié)（8bit）為單位進行收發(fā)時，可以只使用數據寄存器的bit0~bit7，也可以使用bit0~bit32（或bit0~bit23），此時SEI引擎會自動將數據每8bit為一個單位，增加起始位、奇偶校驗位、結束位等進行收發(fā)。例如有一個24bit的編碼器單圈位置數據，接收時雖然每8bit接收1包，但連續(xù)收到的3包數據會放到同一個數據寄存器內；發(fā)送時，用戶在數據寄存器的bit0~bit23填入數據，SEI引擎會自動拆包，將bit0~bit7、bit8~bit15、bit16~bit23分別增加起始位、奇偶校驗位、結束位對外發(fā)出。

數據寄存器0用于忽略接收到的數據——某些開發(fā)者不關心的數據可以使用數據數據寄存器0進行接收；其概念與linux系統(tǒng)下黑洞文件類似。

數據寄存器2~數據寄存器9為通用數據寄存器?？梢怨ぷ髟?種模式下：

1）數據模式：僅用于存儲數據；

2）檢查模式：可設定期待值，例如用戶期待接收到0x17，當接收到的寫入該數據寄存器的值不為0x17時，可產生傳輸錯誤提示；

3）CRC模式：用于收發(fā)數據過程中實時計算CRC值，可通過設置CRC多項式與CRC初始值來設計CRC算法，當接收數據的CRC計算結果與實時計算結果不符時，可產生錯誤傳輸提示。

1.1.2命令寄存器

用于接收串行編碼器協議中的命令數據。例如Tamagawa協議中CF（Control Field）字段為命令，其含義如下圖：

可以看到，CF字段內的cc0~cc3決定了通信的內容，根據該字段的不同，主機可以從編碼器中讀取單圈位置數據、多圈位置數據、報警信息、操作EEPROM等。

1.1.3命令匹配表

命令寄存器接收到命令后，SEI引擎接收JUMP跳轉指令，會根據命令內容在命令匹配表內進行檢索。找到符合命令的表項后，則跳轉至該命令匹配表指向的指令開始執(zhí)行。SEI共支持8張命令匹配表，SEI引擎會以順序方式對每張命令匹配表的命令進行對比，如果命令匹配表0~命令匹配表6都匹配失敗，則無條件執(zhí)行命令匹配表7的預設指令（回復/不回復）。

1.1.4指令

SEI引擎共支持8種指令，分為停止、等待、接收、發(fā)送、跳轉5大類指令，根據是否有超時保護拓展為8種指令。例如接收指令可分為時限內接收與無限時接收，時限內接收在規(guī)定的時間內未收到數據會進行報錯處理，無限時接收則會永遠等待下去。其它時限內發(fā)送與無限時發(fā)送等概念，請讀者自行理解。SEI共支持預設64條指令。

1.1.5狀態(tài)機

SEI狀態(tài)機包括4個狀態(tài)，狀態(tài)的切換只能以0-->1-->2-->3-->0的順序進行，每種狀態(tài)的切換條件可由開發(fā)者自行定義，例如設置執(zhí)行完第10條指令后狀態(tài)機從狀態(tài)0切換到狀態(tài)1。狀態(tài)切換可向外發(fā)送事件信號，開發(fā)者可將該信號拉到其它外設進行觸發(fā)，實現硬件同步；或簡單的產生一次中斷或DMA事件，使用中斷或DMA進行一定的數據處理工作。

理解SEI工作的關鍵就在于以上5個概念的掌握。其它更多的技術細節(jié)需要讀者自行查閱UM手冊進行理解。下面就以這5個概念對SEI工作的流程進行直觀的舉例描述：

1）從機開始以指令0“接收”狀態(tài)等待主機發(fā)送CF字段，若接收到數據，將接收到的指令保存到指令寄存器；

2）例如收到了DATA ID3指令，接收到指令后檢查指令匹配表；

3）順序檢查8張指令匹配表進行指令匹配，例如匹配到了指令表1，該指令表內描述“收到DATA ID3后執(zhí)行預設的64條指令中的指令10”；

4）SEI引擎執(zhí)行指令10，指令10內容為“時限內發(fā)送，CF，CF存放于指令寄存器”；

5）SEI引擎執(zhí)行指令11，指令11內容為“時限內發(fā)送，SF，SF存放于數據寄存器2”；

6）SEI引擎執(zhí)行指令12，指令12內容為“時限內發(fā)送，ABS0~ABS2，ABS存放于數據寄存器3”；

7）SEI引擎執(zhí)行指令13，指令13內容為“時限內發(fā)送，ENID，ENID存放于數據寄存器4”；

8）SEI引擎執(zhí)行指令14，指令14內容為“時限內發(fā)送，ABM，ABM存放于數據寄存器5”；

9）SEI引擎執(zhí)行指令15，指令15內容為“時限內發(fā)送，ALC，ALC存放于數據寄存器6”;

10）SEI引擎執(zhí)行指令16，指令16內容為“時限內發(fā)送，CRC，CRC存放于數據寄存器9”；

11）SEI引擎執(zhí)行指令17，指令17內容為“結束，跳轉回指令0”；

12）SEI引擎執(zhí)行指令0，指令0內容為“接收，等待主機發(fā)送CF字段，若接收到數據，將接收到的指令保存到指令寄存器”。

可以看到，通過以上工作流程的描述，SEI就依靠硬件自動完成了數據的發(fā)送，響應了主機讀數據的需求。CPU只要在合適的時間點將數據更新到數據寄存器即可。

2 多摩川協議簡介

多摩川編碼器在工業(yè)控制領域廣泛應用，本節(jié)簡單介紹Tamagawa編碼器協議。

注意，協議整體架構是固定的，但具體到每款編碼器，根據編碼器精度不同、多圈數據位數不同，協議的數據內容需要進行微調。

多摩川編碼器支持向主站提供單圈位置信息、多圈位置信息、報警信息、復位操作、EEPROM讀寫操作等，不同操作指令的下發(fā)位于CF字段內。下面分別介紹協議內不同指令的具體格式。

具體的，多摩川協議以2.5M固定波特率進行數通信，數據格式8、N、1。

2.1數據讀取指令格式

數據讀取過程：

1）主機下發(fā)CF，CF內的cc0~cc3為ID0~ID3時，代表讀取編碼器信息；

2）從機回復CF，響應主機；

3）從機回復SF，發(fā)送編碼器狀態(tài)信息（具體有什么狀態(tài)Flag請讀者自行學習多摩川編碼器Datasheet）；

4）從機回復DF0~DF7，即數據字段。根據不同的指令ID，數據字段長度不同，數據字段內可包含ABS（單圈信息），ENID（固定0x17）,ABM（多圈信息），ALMC（報警信息），不同ID回復內容見下表。

5）從機回復CRC，供主機進行數據完整性校驗。

時序要求如下，在收到CF后的0.5us時刻鎖存當前位置信息：

2.2EEPROM讀指令格式

多摩川編碼器為客戶提供了762字節(jié)的EEPROM空間，分為6頁，每頁包含127個（0~126）字節(jié)。對地址127進行寫操作可改變操作頁數。

1）主機發(fā)送CF，CF內cc0~cc3字段解析為ID D；

2）主機發(fā)送ADF，代表要讀取當前頁的第ADF個（0~126）字節(jié)的數據；

3）主機發(fā)送CRC，供從機進行數據完整性校驗；

4）從機回復CF、ADF；

5）從機回復EDF，即主機需要的數據；

6）從機回復CRC，供主機進行數據完整性校驗。

2.3EEPROM寫指令格式

1）主機發(fā)送CF，CF內cc0~cc3字段解析為ID 6；

2）主機發(fā)送ADF，代表要寫入當前頁的第ADF個（0~126）字節(jié)；

3）主機發(fā)送EDF，代表要寫入的數據；

4）主機發(fā)送CRC，供從機進行數據完整性校驗；

5）從機回復CF、ADF、EDF、CRC，與主機下發(fā)內容相同，代表寫入成功。

讀寫時序要求如下：

3多摩川從站例程介紹

打開

sdk_env_v1.5.0\hpm_sdk\samples\drivers\sei\slave\tamagawa\src文件，獲取Tamagawa從站源碼。

/* [1] tranceiver config */

tranceiver_config.mode=sei_asynchronous_mode;

tranceiver_config.tri_sample= false;

tranceiver_config.src_clk_freq=clock_get_frequency(BOARD_MOTOR_CLK_NAME);

tranceiver_config.asynchronous_config.wait_len =0;

tranceiver_config.asynchronous_config.data_len =8;

tranceiver_config.asynchronous_config.parity_enable=false;

tranceiver_config.asynchronous_config.data_idle_high_z =false;

tranceiver_config.asynchronous_config.data_idle_state= sei_idle_high_state;

tranceiver_config.asynchronous_config.baudrate= 2500000;

sei_tranceiver_config_init(BOARD_SEI,BOARD_SEI_CTRL,&tranceiver_config);

設置SEI工作在異步模式，波特率為2.5M，數據格式為8、N、1。以及數據線的默認狀態(tài)等，這一部分請讀者自行對照UM手冊SEI寄存器進行解析。

/* [2] data register config */

/* cmd register : recv CF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_CMD,BOARD_SEI_CTRL,&data_format_config);

/* data register 4: send SF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_4, &data_format_config);

/* data register 5: send ABS0 ABS1 ABS2 */

data_format_config.mode=sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order=sei_word_nonreverse;

data_format_config.word_len= 24;

data_format_config.last_bit= 23;

data_format_config.first_bit= 0;

data_format_config.max_bit= 23;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_5, &data_format_config);

/* data register 6: send ENID */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order=sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_6, &data_format_config);

/* data register 7: send ABM0 ABM1 ABM2 */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order=sei_word_nonreverse;

data_format_config.word_len= 24;

data_format_config.last_bit= 23;

data_format_config.first_bit= 0;

data_format_config.max_bit= 23;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_7, &data_format_config);

/* data register 8: send ALMC */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order=sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_8, &data_format_config);

/* data register 9: send crc */

data_format_config.mode= sei_crc_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order=sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.crc_invert= false;

data_format_config.crc_shift_mode= false;

data_format_config.crc_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

data_format_config.crc_init_value= 0;

data_format_config.crc_poly= 1;

sei_cmd_data_format_config_init

(BOARD_SEI, SEI_SELECT_DATA, SEI_DAT_9, &data_format_config);

設置數據寄存器，其中：

1）指令寄存器用于收發(fā)CF；

2）DATA4(數據寄存器4)用于發(fā)送SF；

3）DATA5(數據寄存器5)用于發(fā)送ABS；

4）DATA6(數據寄存器6)用于發(fā)送ENID；

5）DATA7(數據寄存器7)用于發(fā)送ABM；

6）DATA8(數據寄存器8)用于發(fā)送ALM；

7）DATA9(數據寄存器9)用于發(fā)送CRC；

/* [3] instructions */

instr_idx= 0;

/* instr0 : Recv CF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_0, SEI_DAT_1, 8);

/* instr1 : halt 1 bit for update */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 1);

/* instr2 : halt some bits for waiting */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 6);

/* instr3 : jump to cmd table instr_idx[0] */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_CMD_TABLE_INSTR_IDX0);

/* Data ID0 : 0x02 */

/*instr4 : sendCF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);

/* instr5 : send SF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);

/*instr6 :send ST(POS) */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_5, 24);

/*instr7 :CRC */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);

/*instr8 :Jump back to initiate*/

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID1 : 0x8A */

/* Reference to instr0 ~ instr8 */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);/* CF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);/* SF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_7, 24);/* MT */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8); /* CRC */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID2 : 0x92 */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);/* CF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8); /* SF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_6, 8);/* ENID:0x17 */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID3 : 0x1A */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);/* CF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8); /* SF */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_5, 24);/* ST(POS) */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_6, 8);/* ENID:0x17 */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_7, 24);/* MT */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_8, 8);/* ALMC */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

設置預設指令，其中：

1）指令0用于接收CF；

2）指令1用于延遲0.5us后鎖存位置信息；

3）指令2用于延遲3us滿足時序要求；

4）指令3用于跳轉，查找指令匹配表進行匹配；

5）指令4~指令表結束，根據不同的指令向主機發(fā)送主機查詢的信息。

/* [4] command table */

command_table_config.cmd_min_value= 0x02u;

command_table_config.cmd_max_value= 0x02u;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 4;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_0, &command_table_config);

command_table_config.cmd_min_value= 0x8Au;

command_table_config.cmd_max_value= 0x8Au;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 9;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_1, &command_table_config);

command_table_config.cmd_min_value= 0x92u;

command_table_config.cmd_max_value= 0x92u;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 14;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_2,&command_table_config);

command_table_config.cmd_min_value= 0x1Au;

command_table_config.cmd_max_value= 0x1Au;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 19;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_3,&command_table_config);

設置指令匹配表，

cmd_min_value、cmd_max_value、cmd_mask_value設置了指令匹配的模式，請參考UM手冊查詢具體的含義；instr_idx[0]設置了如果匹配成功，跳轉的目標指令。

/* [5] state transition config */

/* latch0 */

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= false;

state_transition_config.instr_ptr_cfg= sei_state_tran_condition_fall_leave;

state_transition_config.instr_ptr_value= 1;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_0_1, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_1_2,&state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_2_3, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_3_0, &state_transition_config);

state_transition_latch_config.enable= true;

state_transition_latch_config.output_select= SEI_CTRL_LATCH_TRAN_0_1;

state_transition_latch_config.delay= 0;

sei_state_transition_latch_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0,&state_transition_latch_config);

狀態(tài)機跳轉的配置代碼，此處只配置了狀態(tài)0到狀態(tài)1轉換的條件為“指令1執(zhí)行完成”，即接收到CF后0.5us的時間點，進行狀態(tài)轉換，同時向外生成事件（本例程內產生了中斷，中斷內對要發(fā)送的數據進行了設置）。

/* [6] sample config*/

sample_config.pos_data_idx= SEI_DAT_5;

sample_config.rev_data_idx= SEI_DAT_7;

sample_config.pos_data_use_rx= false;

sample_config.rev_data_use_rx= false;

sample_config.sample_window= 0x5;

sample_config.sample_once= true;

sample_config.latch_select= SEI_LATCH_0;

sample_config.data_register_select= BIT5_MASK| BIT7_MASK; /* SEI_DAT_5, SEI_DAT_7 */

sei_sample_config_init(BOARD_SEI, BOARD_SEI_CTRL,&sample_config);

sei_set_sample_pos_override_value(BOARD_SEI, BOARD_SEI_CTRL, mock_pos);

sei_set_sample_rev_override_value(BOARD_SEI, BOARD_SEI_CTRL,mock_rev);

/* [7] interrupt config */

intc_m_enable_irq_with_priority(BOARD_SEI_IRQn, 1);

sei_set_irq_enable(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch0_event | sei_irq_wdog_event | sei_irq_trx_err_event,true);

采樣設置（讀取電機系統(tǒng)內的位置信息）與中斷開啟，狀態(tài)0到狀態(tài)1實現狀態(tài)轉換時，出發(fā)了sei_irq_latch0_event中斷。

/* [8] enbale sync timer timestamp */

synt_enable_timestamp(HPM_SYNT, true);

/* [9] engine config */

printf("Started sei engine!\n");

engine_config.arming_mode= sei_arming_direct_exec;

engine_config.data_cdm_idx= 0;

engine_config.data_base_idx= 0;

engine_config.init_instr_idx= 0;

engine_config.wdg_enable= true;

engine_config.wdg_action= sei_wdg_exec_exception_instr;

engine_config.wdg_instr_idx= 0;

engine_config.wdg_time= 1000; /* 1000 bits time */

sei_engine_config_init(BOARD_SEI, BOARD_SEI_CTRL,&engine_config);

sei_set_engine_enable(BOARD_SEI, BOARD_SEI_CTRL, true);

看門狗的設置及使能SEI引擎，看門狗的配置含義請參考UM手冊。

voidisr_sei(void)

{

uint32_tdelta;

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch0_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch0_event);

sample_latch_tm1= sei_get_latch_time(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0);

mock_pos++;

if(mock_pos> 0x00FFFFFF) {

mock_pos= 0;

mock_rev++;

if(mock_rev> 0x00FFFFFF) {

mock_rev= 0;

}

}

sei_set_sample_pos_override_value(BOARD_SEI, BOARD_SEI_CTRL, mock_pos);

sei_set_sample_rev_override_value(BOARD_SEI, BOARD_SEI_CTRL, mock_rev);

sei_set_data_value(BOARD_SEI, SEI_DAT_4, 0x00);

sei_set_data_value(BOARD_SEI, SEI_DAT_6, 0x17);

sei_set_data_value(BOARD_SEI, SEI_DAT_8, 0x00);

delta= (sample_latch_tm1> sample_latch_tm2) ? (sample_latch_tm1- sample_latch_tm2) : (sample_latch_tm1- sample_latch_tm2+ 0xFFFFFFFFu);

printf("CMD:%#x, SF:%#x, ST:%#x, ENID:%#x, MT:%#x, ALMC:%#x, CRC:%#x, sample_tm1:%u, sample_tm2:%u, sample_interval:%dus\n",

sei_get_command_value(BOARD_SEI, BOARD_SEI_CTRL),

sei_get_data_value(BOARD_SEI, SEI_DAT_4),

sei_get_data_value(BOARD_SEI, SEI_DAT_5),

sei_get_data_value(BOARD_SEI, SEI_DAT_6),

sei_get_data_value(BOARD_SEI, SEI_DAT_7),

sei_get_data_value(BOARD_SEI, SEI_DAT_8),

sei_get_data_value(BOARD_SEI, SEI_DAT_9),

sample_latch_tm1, sample_latch_tm2, delta/ (clock_get_frequency(BOARD_MOTOR_CLK_NAME) / 1000000));

sample_latch_tm2= sample_latch_tm1;

}

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_wdog_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_wdog_event);

sei_set_command_rewind(BOARD_SEI, BOARD_SEI_CTRL);

}

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_trx_err_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_trx_err_event);

printf("TRX Error!\n");

}

}

SEI中斷設置，當sei_irq_latch0_event中斷發(fā)生時，設置了向主機回復的數據，滿足多摩川時序要求，即接收到CF后0.5us時間點進行數據設置。

4 EEPROM指令支持

由于讀寫EEPROM的指令格式與讀取位置數據指令格式有區(qū)別，即接收CF后不進行鎖存，需要繼續(xù)接收ADF、EDF等數據，因此整個SEI指令處理流程上，指令的跳轉邏輯變得更復雜。下圖是在做EEPROM指令支持開發(fā)過程中，繪制的流程圖。

支持EEPROM指令的關鍵源碼如下：

uint32_teeprom_page= 0;

uint32_teeprom[6][127] = {0};

聲明eeprom地址頁信息變量與6頁共762字節(jié)的eeprom數據數組。

/* [2] data register config */

/* cmd register : recv CF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_CMD, BOARD_SEI_CTRL, &data_format_config);

/* cmd register : recv ADF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_2,&data_format_config);

/* cmd register : recv EDF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_3,&data_format_config);

/* data register 4: send SF */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_4, &data_format_config);

/* data register 5: send ABS0 ABS1 ABS2 */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag=false;

data_format_config.bit_order=sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 24;

data_format_config.last_bit= 23;

data_format_config.first_bit= 0;

data_format_config.max_bit= 23;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_5, &data_format_config);

/* data register 6: send ENID */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_6, &data_format_config);

/* data register 7: send ABM0 ABM1 ABM2 */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 24;

data_format_config.last_bit= 23;

data_format_config.first_bit= 0;

data_format_config.max_bit= 23;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_7,&data_format_config);

/* data register 8: send ALMC */

data_format_config.mode= sei_data_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_8,&data_format_config);

/* data register 9: send crc */

data_format_config.mode= sei_crc_mode;

data_format_config.signed_flag= false;

data_format_config.bit_order= sei_bit_lsb_first;

data_format_config.word_order= sei_word_nonreverse;

data_format_config.word_len= 8;

data_format_config.crc_invert= false;

data_format_config.crc_shift_mode= false;

data_format_config.crc_len= 8;

data_format_config.last_bit= 7;

data_format_config.first_bit= 0;

data_format_config.max_bit= 7;

data_format_config.min_bit= 0;

data_format_config.crc_init_value= 0;

data_format_config.crc_poly= 1;

sei_cmd_data_format_config_init

(BOARD_SEI,SEI_SELECT_DATA, SEI_DAT_9, &data_format_config);

設置數據寄存器，其中：

1）指令寄存器用于收發(fā)CF

2）DATA2(數據寄存器2)用于收發(fā)ADF

3）DATA3(數據寄存器3)用于發(fā)送EDF

4）DATA4(數據寄存器4)用于發(fā)送SF

5）DATA5(數據寄存器5)用于發(fā)送ABS

6）DATA6(數據寄存器6)用于發(fā)送ENID

7）DATA7(數據寄存器7)用于發(fā)送ABM

8）DATA8(數據寄存器8)用于發(fā)送ALM

9）DATA9(數據寄存器9)用于發(fā)送CRC

/* [3] instructions */

instr_idx= 0;

/*00*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_9, SEI_DAT_1, 8);/* Recv CF */

/* jump to cmd */

/*01*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_CMD_TABLE_INSTR_IDX0);/* jump to cmd table instr_idx[0] */

/*02*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 1); /* halt 1 bit for update */

/*03*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 6); /* halt some bits for waiting */

/*04*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_CMD_TABLE_INSTR_IDX6);

/* Data ID0 : 0x02 */

/*05*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8); /* CF */

/*06*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);/* SF */

/*07*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_5, 24);/* ST(POS) */

/*08*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

/*09*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID1 : 0x8A */

/*10*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8); /* CF */

/*11*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);/* SF */

/*12*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_7, 24);/* MT */

/*13*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

/*14*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID2 : 0x92 */

/*15*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);/* CF */

/*16*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);/* SF */

/*17*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_6, 8);/* ENID:0x17 */

/*18*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

/*19*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID3 : 0x1A */

/*20*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8); /* CF */

/*21*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_4, 8);/* SF */

/*22*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_5, 24);/* ST(POS) */

/*23*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_6, 8);/* ENID:0x17 */

/*24*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_7, 24);/* MT */

/*25*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_8, 8); /* ALMC */

/*26*/sei_set_instr(BOARD_SEI,instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

/*27*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

/* Data ID6 : 0x32 */ /*write to eeprom */

/*28*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_9, SEI_DAT_2, 8); /* ADF */

/*29*/sei_set_instr(BOARD_SEI,instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_9, SEI_DAT_3, 8); /* EDF */

/*30*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_0, SEI_DAT_9, 8); /* CRC */

/*31*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_CMD_TABLE_INSTR_IDX6);

/* Data IDD : 0xEA */ /*read from eeprom */

/*32*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_9, SEI_DAT_2, 8);/* ADF */

/*33*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_RECV_WDG, 0, SEI_DAT_0, SEI_DAT_9, 8);/* CRC */

/*34*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_CMD_TABLE_INSTR_IDX6);

/*response to write/read eeprom */

/*35*/sei_set_instr(BOARD_SEI,instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 1); /* halt 1 bit for update */

/*36*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_HALT, 0, SEI_DAT_0, SEI_DAT_0, 6); /* halt some bits for waiting */

/*37*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_1, 8);/* CF */

/*38*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_2, 8); /* ADF */

/*39*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_9, SEI_DAT_3, 8);/* EDF */

/*40*/sei_set_instr(BOARD_SEI, instr_idx++, SEI_INSTR_OP_SEND, 0, SEI_DAT_0, SEI_DAT_9, 8); /* CRC */

/*41*/sei_set_instr(BOARD_SEI,instr_idx++, SEI_INSTR_OP_JUMP, 0, SEI_DAT_0, SEI_DAT_0, SEI_JUMP_INIT_INSTR_IDX);

以上代碼為根據流程圖編寫的新指令預設內容。

/* [4] command table */

command_table_config.cmd_min_value= 0x02u;

command_table_config.cmd_max_value= 0x02u;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 2;

command_table_config.instr_idx[6] = 05;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_0,&command_table_config);

command_table_config.cmd_min_value= 0x8Au;

command_table_config.cmd_max_value= 0x8Au;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 2;

command_table_config.instr_idx[6] = 10;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_1,&command_table_config);

command_table_config.cmd_min_value= 0x92u;

command_table_config.cmd_max_value= 0x92u;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 2;

command_table_config.instr_idx[6] = 15;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_2,&command_table_config);

command_table_config.cmd_min_value= 0x1Au;

command_table_config.cmd_max_value= 0x1Au;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 2;

command_table_config.instr_idx[6] = 20;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_3,&command_table_config);

command_table_config.cmd_min_value= 0x32u;

command_table_config.cmd_max_value= 0x32u;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 28;

command_table_config.instr_idx[6] = 35;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL,SEI_CMD_TABLE_4,&command_table_config);

command_table_config.cmd_min_value= 0xEAu;

command_table_config.cmd_max_value= 0xEAu;

command_table_config.cmd_mask_value= 0xFFu;

command_table_config.instr_idx[0] = 32;

command_table_config.instr_idx[6] = 35;

sei_cmd_table_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_CMD_TABLE_5,&command_table_config);

以上代碼為根據流程圖編寫的新指令匹配表。

/* [5] state transition config */

/* latch0 */

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= false;

state_transition_config.instr_ptr_cfg= sei_state_tran_condition_fall_leave;

state_transition_config.instr_ptr_value= 2;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_0_1, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_1_2, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_2_3, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0, SEI_CTRL_LATCH_TRAN_3_0,&state_transition_config);

state_transition_latch_config.enable= true;

state_transition_latch_config.output_select= SEI_CTRL_LATCH_TRAN_0_1;

state_transition_latch_config.delay= 0;

sei_state_transition_latch_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0,&state_transition_latch_config);

/* [6] state transition config */

/* latch1 */

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= false;

state_transition_config.instr_ptr_cfg= sei_state_tran_condition_fall_leave;

state_transition_config.instr_ptr_value= 35;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_1, SEI_CTRL_LATCH_TRAN_0_1, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL,SEI_LATCH_1, SEI_CTRL_LATCH_TRAN_1_2, &state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_1, SEI_CTRL_LATCH_TRAN_2_3,&state_transition_config);

state_transition_config.disable_clk_check= true;

state_transition_config.disable_txd_check= true;

state_transition_config.disable_rxd_check= true;

state_transition_config.disable_timeout_check= true;

state_transition_config.disable_instr_ptr_check= true;

sei_state_transition_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_1, SEI_CTRL_LATCH_TRAN_3_0, &state_transition_config);

state_transition_latch_config.enable= true;

state_transition_latch_config.output_select= SEI_CTRL_LATCH_TRAN_0_1;

state_transition_latch_config.delay= 0;

sei_state_transition_latch_config_init(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_1,&state_transition_latch_config);

鎖存器0配置為執(zhí)行完指令2（讀取位置信息CF的0.5us鎖存點）后進行位置鎖存；

鎖存器1配置為執(zhí)行完指令35（操作EEPROM指令CRC后0.5us鎖存點）后進行EEPROM操作；

voidisr_sei(void)

{

uint32_tdelta;

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch0_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch0_event);

sei_set_data_rewind(BOARD_SEI,SEI_DAT_9);

sample_latch_tm1= sei_get_latch_time(BOARD_SEI, BOARD_SEI_CTRL, SEI_LATCH_0);

mock_pos++;

if(mock_pos> 0x00FFFFFF) {

mock_pos= 0;

mock_rev++;

if(mock_rev> 0x00FFFFFF) {

mock_rev= 0;

}

}

sei_set_sample_pos_override_value(BOARD_SEI, BOARD_SEI_CTRL, mock_pos);

sei_set_sample_rev_override_value(BOARD_SEI, BOARD_SEI_CTRL, mock_rev);

sei_set_data_value(BOARD_SEI, SEI_DAT_4, 0x00);

sei_set_data_value(BOARD_SEI, SEI_DAT_6, 0x17);

sei_set_data_value(BOARD_SEI, SEI_DAT_8, 0x00);

delta= (sample_latch_tm1> sample_latch_tm2) ? (sample_latch_tm1- sample_latch_tm2) : (sample_latch_tm1- sample_latch_tm2+ 0xFFFFFFFFu);

printf("CMD:%#x, SF:%#x, ST:%#x, ENID:%#x,MT:%#x, ALMC:%#x, CRC:%#x,sample_tm1:%u,sample_tm2:%u, sample_interval:%dus\n",

sei_get_command_value(BOARD_SEI, BOARD_SEI_CTRL),

sei_get_data_value(BOARD_SEI, SEI_DAT_4),

sei_get_data_value(BOARD_SEI, SEI_DAT_5),

sei_get_data_value(BOARD_SEI, SEI_DAT_6),

sei_get_data_value(BOARD_SEI, SEI_DAT_7),

sei_get_data_value(BOARD_SEI, SEI_DAT_8),

sei_get_data_value(BOARD_SEI, SEI_DAT_9),

sample_latch_tm1, sample_latch_tm2, delta/ (clock_get_frequency(BOARD_MOTOR_CLK_NAME) / 1000000));

sample_latch_tm2= sample_latch_tm1;

}

elseif(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch1_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_latch1_event);

uint32_tcmd= sei_get_command_value(BOARD_SEI, SEI_CTRL_1);

if(cmd== 0x32u) {

uint32_taddr= sei_get_data_value(BOARD_SEI, SEI_DAT_2);

uint32_tdata= sei_get_data_value(BOARD_SEI, SEI_DAT_3);

if(addr== 127) {

eeprom_page= data;

}else{

eeprom[eeprom_page][addr] = data;

}

}elseif(cmd== 0xEAu) {

uint32_taddr= sei_get_data_value(BOARD_SEI, SEI_DAT_2);

sei_set_data_value(BOARD_SEI, SEI_DAT_3, eeprom[eeprom_page][addr]);

}

}

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_wdog_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_wdog_event);

sei_set_command_rewind(BOARD_SEI, BOARD_SEI_CTRL);

printf("WDG!\n");

}

if(sei_get_irq_status(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_trx_err_event)) {

sei_clear_irq_flag(BOARD_SEI, BOARD_SEI_CTRL, sei_irq_trx_err_event);

printf("TRX Error!\n");

}

}

在中斷內，sei_irq_latch0_event分支處理位置鎖存信息；sei_irq_latch1_event根據收到的指令信息對eeprom數組和地址頁進行操作，更新數據/設置回復數據。

5 小結

相信通過以上針對SEI的講解，及對多摩川協議、例程代碼的分析與修改，讀者對SEI有了更深的認識，希望開發(fā)者可以用好SEI模塊，加速項目開發(fā)與落地。