Specifications

S1C62740 TECHNICAL SOFTWARE EPSON II-23
CHAPTER 6: PERIPHERAL CIRCUITS (Output Ports)
Following program shows the output ports controlling procedure in
ordinary DC output case.
Loading B register data into R00–R03
Label Mnemonic/operand Comment
Example program
for the general
output ports
;*
;* OUTPUT PORT
;*
;* LOADING DATA OF B REGISTER TO R00-R03
;
ZR0 EQU 0D4H ;R0 OUTPUT PORT
ZBZCTL EQU 0E0H ;BUZZER CONTROL REGISTER
BZR03 EQU 1000B ;R03 PORT OUTPUT SELECTION
BZR02 EQU 0100B ;R02 PORT OUTPUT SELECTION
ZFOCTL EQU 0E1H ;FOUT CONTROL REGISTER
FOR00 EQU 1000B ;R00 OUTPUT PORT SELECTION
ZPTC EQU 0E9H ;PROGRAMMABLE TIMER CONTROL REGISTER
PTR01 EQU 1000B ;R01 PORT OUTPUT SELECTION
;
LD X,ZBZCTL ;DISABLE BUZZER OUTPUT TO R03 & R02
AND MX,(NOT (BZR02 OR BZR03)) AND 0FH
LD X,ZFOCTL ;DISABLE FOUT OUTPUT TO R00
AND MX,(NOT FOR00) AND 0FH
LD X,ZPTC ;DISABLE PTOVF OUTPUT TO R01
AND MX,(NOT PTR01) AND 0FH
;
LD X,ZR0 ;SET OUTPUT PORT ADDRESS
LD MX,B ;OUTPUT B REGISTER TO R0 PORT
;
As shown in Figure 6.4.1, the above program loads the data of the
B register into the output ports.
D3 D2 D1 D0
Data register
R00
Data register
R01
Data register
R02
Data register
R03
B register
Fig. 6.4.1
Correspondence between output
ports (R00–R03) and B register
The output data can be taken from the A register, MX, or immedi-
ate data instead of B register.