GMS30004 Datasheet, PDF (38/158 Pages) Hynix Semiconductor – 4-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 3. Instruction
(17) RTN
Naming :
Status :
Format :
Function :
<Purpose>
<Comment>
Return from Subroutine
é^Set
PC à SR1
PA, PB à PSR1
SR1 à SR2
PSR1 à PSR2
SR2 à SR3
PSR2 à PSR3
SR3 à SR3
PSR3 à PSR2
ST à 1
Control is returned from the called subroutine to the calling
program.
Control is returned to its home routine by transferring to the PC
the data of the return address that has been saved in the stack
register (SR1).
At the same time, data of the page stack register (PSR1) is
transferred to the PA and PB.
(18) LPBI i
Naming :
Status :
Format :
Operand :
Function :
<Purpose>
<Comment>
Load Page Buffer Register from Immediate
ë^Set
ROM page address 0 õ i õ 15
PB à i
A new ROM page address is loaded into the page buffer
register (PB).
This loading is necessary for a long branch or call instruction.
The PB register is loaded together with three bits from 4 bit
operand.
(19) AM
Naming :
Status :
Format :
Function :
<Comment>
Add Accumulator to Memory and Status 1 on Carry
é^{Carry to status}
A à M(X,Y)+A, ST à 1(when total>15),
ST à 0 (when total õ15)
Data in the memory location addressed by the X and Y-register
is added to data of the accumulator. Results are stored in the
accumulator. Carry data as results is transferred to status.
When the total is more than 15, a carry is caused to put Ì1Ì
in the status. Data in the memory is not changed.
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