Manualsbrain.com
  1. Manuals
  2. Brands
  3. NEC
  4. PD750008
  5. User Manual

NEC PD750008 User Manual

Download
Page of 342
3 2
µPD750008 USER'S MANUAL
(c) Specific 1-bit direct addressing (@H+mem.bit)
This addressing mode enables any bit in the data memory space to be manipulated.
In this addressing mode, the high-order four bits of the data memory address in the memory bank
specified by MB = MBE·MBS are indirectly specified using the H register, and the low-order four bits
and bit address are directly specified in the operand.  This addressing mode enables a wide variety
of manipulations for each bit in the entire data memory space.
Example Bit 2 at address 32H (FLAG3) is reset if both bit 3 at address 30H (FLAG1) and bit 0 at
address 31H (FLAG2) are set to 0 or 1.
FLAG1
EQU
30H.3
FLAG2
EQU
31H.0
FLAG3
EQU
32H.2
SEL
MB0
MOV
H,#FLAG1 SHR 6
MOV1
CY, @H+FLAG1
; CY <– FLAG1
XOR1
CY, @H+FLAG2
; CY <– CY
FLAG2
MOV1
@H+FLAG3, CY
; FLAG3 <– CY
FLAG3
FLAG1
FLAG2