Specifications

II-26 EPSON S1C6S2N7 TECHNICAL SOFTWARE
CHAPTER 3: PERIPHERAL CIRCUITS (I/O Ports)
• Loading P00–P03 input data into A register
Label Mnemonic/operand Comment
LD Y,0FCH ;Set address of I/O control port
AND MY,1110B ;Set port as input port
LD Y,0F6H ;Set address of port
LD A,MY ;A register ← P00–P03
As shown in Figure 3.4.1, the four instruction steps above
load the data of the I/O ports into the A register.
D3
P03
D2
P02
D1
P01
D0
P00
A register
Examples of I/O port
control program
Fig. 3.4.1
Loading into the A register