Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 2 CPU and Memory Space
FEUL620Q504 2–10
2.7.3 Description of Operation
When using the multiplication/division function, see "MULDIVU8LIB User's Manual" for the available
multiplication/division library.
The following example shows a program for multiplication without using the library.
; 0x1234H × 0x0AA55H multiplication example
MOV R2 ,#55H ; Set the multiplier
MOV R3 ,#0AAH ;
MOV R0 ,#34H ; Set the multiplicand
MOV R1 ,#12H ;
MOV CR4 ,R0 ; Transfer the multiplier [7:0]
MOV R0 ,#90H ; Set the operation mode
MOV CR8 ,R0 ; Set the signed operation mode
MOV CR5 ,R1 ; Transfer the multiplier [15:8]
MOV CR6 ,R2 ; Transfer the multiplicand [7:0]
MOV CR7 ,R3 ; Transfer the multiplicand [15:8] and start the operation
NOP ; Operating. Waiting for end of operation (1 clock)
BAL READ ; Operating. Waiting for end of operation. Unconditionally branch to next
instruction (3 clocks)
;End of operation
READ:
MOV R0 ,CR0 ; Transfer the product [7:0]
MOV R1 ,CR1 ; Transfer the product [15:8]
MOV R2 ,CR2 ; Transfer the product [23:16]
MOV R3 ,CR3 ; Transfer the product [31:24]