(2) Subroutine instruction:
EM73P461A
4-BIT MICRO-CONTROLLER FOR LCD PRODUCT
Preliminary
SCALL a
Object code: 1110 nnnn
Condition : PC ← a ; a=8n+6 ; n=1..15 ; a=86h, n=0
PC 0 0 0 0 a a a a a a a a
LCALL a
Object code: 0100 0 aaa aaaa aaaa
Condition: PC ← a
PC 0 a a a a a a a a a a a
RET
Object code: 0100 1111
Condition: PC ← STACK[SP]; SP + 1
PC The return address stored in stack
(for 4K ROM)
PC The return address stored in stack
(for 8K ROM)
RT I
Object code: 0100 1101
Condition : FLAG. PC ← STACK[SP]; EI ← 1; SP + 1
PC The return address stored in stack
(for 4K ROM)
PC The return address stored in stack
(for 8K ROM)
(3) Interrupt acceptance operation:
When an interrupt is accepted, the original PC is pushed into stack and interrupt vector will be loaded into
PC,The interrupt vectors are as following:
INT0 (External interrupt from P8.2)
PC 0 0 0 0 0 0 0 0 0 0 1 0
(for 4K ROM)
PC 0 0 0 0 0 0 0 0 0 0 0 1 0 (for 8K ROM)
TRGA (Timer A overflow interrupt)
PC 0 0 0 0 0 0 0 0 0 1 1 0
(for 4K ROM)
PC 0 0 0 0 0 0 0 0 0 0 1 1 0 (for 8K ROM)
* This specification are subject to be changed without notice.
12.27.2001 10