CORE8051-APB总线

1 APB总线

core8051s内核支持APB3总线，APB writebuffer 为{XWB3, XWB2, XWB1, ACC};

写访问

对FC00以上地址写值，即表示APB写操作，值为(XWB3, XWB2, XWB1, ACC)。

MOV DPTR, #0FC20H

MOVX @DPTR, A

读访问

MOV DPTR, #0FC20H

MOVX A, @DPTR即可更新 (XWB3, XWB2, XWB1, ACC)。

2 APB汇编示例

FC00-FFFFH空间映射了1个1K的SRAM，通过APB总线来读写。

apb3.asm

    XWB3 EQU   9CH

    XWB2 EQU   9BH

    XWB1 EQU   9AH

    XRB3 EQU   9FH

    XRB2 EQU   9EH

    XRB1 EQU   9DH

main:

     MOV R7, #0H

     MOV DPTR, #0ff40H

     MOV XWB3, #10H

     MOV XWB2, #10H

     MOV XWB1, #10H

     MOV ACC,  #10H

LOOP:

     MOVX @DPTR, A  ;apb write 

     MOVX A, @DPTR  ; apb read 

     ;display

     MOV SBUF, XRB3

     MOV SBUF, XRB2

     MOV SBUF, XRB1

     MOV SBUF, A

     INC DPTR

     INC R7

     INC XWB3

     INC XWB2

     INC XWB1

     MOV ACC, #10H

     ADD A, R7

     CJNE R7, #010H , LOOP 

     SJMP $

执行结果：

write op @f40: 10101010

read op @f40: 10101010

write op @f41: 11111111

read op @f41: 11111111

write op @f42: 12121212

read op @f42: 12121212

write op @f43: 13131313

read op @f43: 13131313

write op @f44: 14141414

read op @f44: 14141414

write op @f45: 15151515

read op @f45: 15151515

write op @f46: 16161616

read op @f46: 16161616

write op @f47: 17171717

read op @f47: 17171717

write op @f48: 18181818

read op @f48: 18181818

write op @f49: 19191919

read op @f49: 19191919

write op @f4a: 1a1a1a1a

read op @f4a: 1a1a1a1a

write op @f4b: 1b1b1b1b

read op @f4b: 1b1b1b1b

write op @f4c: 1c1c1c1c

read op @f4c: 1c1c1c1c

write op @f4d: 1d1d1d1d

read op @f4d: 1d1d1d1d

write op @f4e: 1e1e1e1e

read op @f4e: 1e1e1e1e

write op @f4f: 1f1f1f1f

read op @f4f: 1f1f1f1f

巴特西

CORE8051-APB总线

1 APB总线

写访问

读访问

2 APB汇编示例

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