UPD77111 NEC, UPD77111 Datasheet - Page 35

• Manufacturer Part Number: UPD77111
• Description: 16-BIT FIXED-POINT DIGITAL SIGNAL PROCESSORS
• Manufacturer: NEC

(b) Modifying data pointer
(c) Instructions that can be simultaneously written
(d) Status of overflow flag (OV)
The data pointer is modified after the memory has been accessed. The result of modification becomes valid
starting from the instruction that immediately follows. The data pointer cannot be modified.
Instructions that can be simultaneously written are indicated by O.
The status of the overflow flag is indicated by the following symbol:
z: Not affected
DPn
DPn++
DPn
DPn##
DPn%%
!DPn##
DPn##imm
: Set to 1 when overflow occurs
Caution If an overflow does not occur as a result of an operation, the overflow flag is not reset but
Example
retains the status before the operation.
Nothing is done (value of DPn is not changed.)
DPn
DPn
DPn
(Adds value of corresponding DN0 to DN7 to DP0 to DP7.)
Example: DP0
(n = 0 - 3) DPn = ((DP
(n = 4 - 7) DPn = ((DP
Reverses bits of DPn and then accesses memory.
After memory access, DPn
DPn
DPn + 1
DPn
DPn + DNn
DPn + imm
1
Data Sheet U12801EJ4V0DS00
DP0 + DN0
L
L
+ DNn) mod (DMX + 1)) + DP
+ DNn) mod (DMY + 1)) + DP
DPn + DNn
Operation
PD77110, 77111, 77112
H
H
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