DM-COP8/20D National Semiconductor, DM-COP8/20D Datasheet - Page 125

• Manufacturer Part Number: DM-COP8/20D
• Description: CABLE FOR DEBUG MODULE 20-DIP
• Manufacturer: National Semiconductor

Specifications of DM-COP8/20D

• Accessory Type: 20-DIP Target Cable
• For Use With/related Products: MetaLink Debug Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *DM-COP8/20D

Address Mode:
Description:
Operation:
Instruction
LAID
The LAID instruction uses the contents of the accumulator to point to a
fixed data table stored in program memory. The data table usually rep-
resents a translation matrix, such as the input from a keyboard or the
output to a display.
The contents of the accumulator are exchanged with the contents of PCL
(Lower 8 bits of PC). The data accessed from the program memory loca-
tion addressed by PC is then transferred to the accumulator. Simulta-
neously, the original contents of PCL are transferred back to PCL from
the accumulator. It should be observed that PCU (Upper 7 bits of PC) is
not changed during the LAID instruction, so that the load accumulator
indirect along with the associated fixed data table must both be located
in the current memory page of 256 bytes. However, if the LAID instruc-
tion is located at the last address of the page, the PC counter will have
already incremented over the page boundary resulting in the operand
being fetched from the next page. Consequently, in this instance, the
fixed data table must reside in the next page of 256 bytes in the program
memory.
A <- Program Memory (PCU, A)
Indirect
INDIRECT
Addressing Mode
Instruction
Cycles
COP8SAx7 MICROCONTROLLER
3
Bytes Hex Op Code
1
A4
2-87