Chapter 5. INSTRUCTION
(17) RTN
Naming :
Status :
Return from Subroutine
Set
Format :
Function :
PC
SR1
SR2
SR3
SR3
PA, PB
PSR1
PSR2
PSR3
ST
PSR1
PSR2
PSR3
PSR2
1
SR1
SR2
SR3
<Purpose>
Control is returned from the called subroutine to the calling
program.
<Comment>
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 :
Load Page Buffer Register from Immediate
Set
Format :
Operand :
Function :
<Purpose>
ROM page address 0
PB
A new ROM page address is loaded into the page buffer
register (PB).
i
15
i
This loading is necessary for a long branch or call instruction.
The PB register is loaded together with three bits from 4 bit
operand.
<Comment>
(19) AM
Naming :
Status :
Add Accumulator to Memory and Status 1 on Carry
Carry to status
Format :
Function :
A
M(X,Y)+A, ST
ST
1(when total>15),
0 (when total 15)
<Comment>
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 1
in the status. Data in the memory is not changed.
5-10
HYNIX [ HYNIX SEMICONDUCTOR ]
