![background image](http://html1.mh-extra.com/html/omron/c500-asc04/c500-asc04_operation-manual_743033124.webp)
Appendix C
PC Statements and Refresh Timing
116
PC READ
In four-word mode, when the PC’s WRITE flag is set, the base address is transferred. By the next I/O refresh the
data is read.
I/O Refresh
ASCII Unit
C500 CPU
Instruction Execution
I/O Refresh
I/O Refresh
I/O Refresh
Write Flag (word n bit 01)
* ASCII Busy (word n+3 bit 00)
Instruction Execution
Instruction Execution
PC READ statement
READ
Transfer Words
First Transfer Word
* When PC READ is executed in two-word mode using READ(88), n+3 becomes n+1.
PC WRITE
In four-word mode, when the PC’s READ flag is set during I/O refresh, the PC WRITE statement obtains the base
word address and the number of words to be transferred. With the next I/O refresh, data is transferred.
I/O Refresh
ASCII Unit
C500 CPU
Instruction Execution
I/O Refresh
I/O Refresh
I/O Refresh
READ Flag (word n bit 02)
* ASCII Busy (word n+3 bit 00)
Instruction Execution
Instruction Execution
PC WRITE statement
Transfer Words
First Transfer Word
WRITE
* When PC WRITE is executed in two-word mode using WRIT(87), n+3 becomes n+1.
Summary of Contents for C500-ASC04
Page 1: ...C500 ASC04 ASCII Unit Operation Manual Revised February 2001 ...
Page 5: ...iv ...
Page 7: ...vi ...