NEC PD754144 User Manual page 43

CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP
(c) Special 1-bit direct addressing (@H+mem.bit)
This addressing mode enables bit manipulation in the entire memory space.
The higher 4 bits of the data memory address of the memory bank specified by MBE and MBS are indirectly
specified by the H register, and the lower 4 bits and the bit address are directly specified by the operand.
This addressing mode can be used to manipulate the respective bits of the entire data memory area in
various ways.
Example To reset bit 2 (FLAG3) at address 32H if both bit 3 (FLAG1) at address 30H and bit 0 (FLAG2) at address
31H are 0 or 1
FLAG1 EQU
FLAG2 EQU
FLAG3 EQU
SEL
MOV
CLR1
OR1
XOR1
SET1
SKT
CLR1
FLAG1
FLAG2
30H.3
31H.0
32H.2
MB0
H, #FLAG1 SHR 6
CY ← 0
CY ;
CY ← CY
CY, @H+FLAG1 ;
CY ← CY
CY, @H+FLAG2 ;
FLAG3 ← 1
@H+FLAG3 ;
CY ; CY = 1?
FLAG3 ← 0
@H+FLAG3 ;
User's Manual U10676EJ3V0UM
FLAG3
FLAG1
FLAG2
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