Specifications

II-30 EPSON S1C62N82 TECHNICAL SOFTWARE
CHAPTER 3: PERIPHERAL CIRCUITS (I/O Ports)
• Loading contents of B register into P00–P03
Label Mnemonic/operand Comment
LD Y,0FCH ;Set the address of input/output
;port control register
OR MY,0001B ;Set port as output port
LD Y,0F6H ;Set the address of port
LD MY,B ;P00–P03 ← B register
As shown in Figure 3.5.3, the four instruction steps above
load the data of the B register into the I/O ports.
D3 D2 D1 D0
Data register
P00
Data register
P01
Data register
P02
Data register
P03
B register
Fig. 3.5.3
Control of the I/O port (output)
The output data can be taken from the A register, MX, or
immediate data instead of the B register.
Bit-unit operation for the I/O port is identical to that for the
input ports (K00–K03, K10) or output ports (R00–R03).