13 input/output instructions, Out portn, a – NEC PD754144 User Manual
Page 288
CHAPTER 11 INSTRUCTION SET
288
User’s Manual U10676EJ3V0UM
11.4.13 Input/output instructions
IN A, PORTn
Function: A
←
PORTn n = N
3-0
: 3, 6, 7, 8
Transfers the contents of a port specified by PORTn (n = 3, 6, 7, 8) to the A register.
Caution
When this instruction is executed, it is necessary that MBE = 0 or (MBE = 1, MBS = 15). n can be 3, 6, 7, 8.
The data of the output latch is loaded to the A register in the output mode, and the data of the port pins are loaded
to the register in the input mode.
OUT PORTn, A
Function: PORTn
←
A n = N
3-0
: 3, 6, 8
Transfers the contents of the A register to the output latch of a port specified by PORTn (n = 3, 6, 8).
Caution
When this instruction is executed, it is necessary that MBE = 0 or (MBE = 1, MBS = 15).
Only 3, 6, and 8 can be specified as n.