COP8SA-DM National Semiconductor, COP8SA-DM Datasheet - Page 124

• Manufacturer Part Number: COP8SA-DM
• Description: MODULE DEBUGGING FOR COP8SA
• Manufacturer: National Semiconductor

Specifications of COP8SA-DM

• Module/board Type: Debugger Module
• For Use With/related Products: Cop 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *COP8SA-DM

Syntax:
Description:
Operation:
2-86
JSRL ADDR
Instruction Addressing Mode
COP8SAx7 MICROCONTROLLER
JSRL ADDR
The JSRL instruction allows the subroutine to be located anywhere in
the 32-Kbyte program memory space. The instruction pushes the return
address onto the software stack in data memory and then jumps to the
subroutine address.
The contents of PCL (Lower 8 bits of PC) are transferred to the data
memory location referenced by SP (Stack Pointer). SP is then decre-
mented, followed by the contents of PCU (Upper 7 bits of PC) being
transferred to the new data memory location referenced by SP. The re-
turn address is now saved on the software stack in data memory RAM.
Then SP is again decremented to set up the software stack reference for
the next subroutine.
Next, the values found in the second and third bytes of the instruction
are transferred to PCU and PCL respectively. The program then jumps
to the program memory location accessed by PC.
[SP] <- PCL
[SP - 1] <- PCU
[SP - 2]: SET UP FOR NEXT STACK REFERENCE
PC14-8 <- HIADDR (SECOND BYTE OF INSTRUCTION)
PC7-0 <- LOADDR (THIRD BYTE OF INSTRUCTION)
Absolute
Instruction
Cycles
5
Bytes
3
Hex Op Code
AD/HIADDR/
LOADDR