Q67120-C0581 查看數據表（PDF） - Siemens AG

零件编号

产品描述 (功能)

生产厂家

Q67120-C0581

8-Bit CMOS Single-Chip Microcontroller Family

Siemens AG 

Memory Organization

Figure 3-4

Use of Port 2 as I/O-Port

At a write to Port 2, XRAM address in XPAGE-register will be overwritten because of the concurrent

write to Port 2 and XPAGE-register. So whenever XRAM is used and the XRAM address differs

from the byte written to Port 2 latch it is absolutely necessary to rewrite XPAGE with page address.

Example:

I/O-Data at Port 2 shall be 0AAH. A Byte shall be fetched from XRAM at address 0F830H

MOV R0, #30H

MOV P2, #0AAH

MOV XPAGE, #0F8H

MOVX A, @R0

; P2 shows 0AAH

; P2 still shows 0AAH but XRAM is addressed

; the contents of XRAM at 0F830H is moved to accu

Semiconductor Group

3-12

Share Link: