UPD77018A NEC, UPD77018A Datasheet - Page 25

• Manufacturer Part Number: UPD77018A
• Description: 16 bits/ Fixed-point Digital Signal Processor
• Manufacturer: NEC

(b) Modifying data pointers
(c) Concurrent processing instructions
(d) State of Overflow flag (OV)
Caution
Description
DPn
DPn++
DPn– –
DPn##
DPn%%
!DPn##
DPn##imm
Data pointers are modified after memory access. The results are valid immediately after instruction execution.
It is impossible to modify without memory access.
Instruction names are shown in abbreviation.
TRI
DYAD
MONAD : Monadic
TRANS
IMM
BR
LOOP
CTR
The following marks show the PD77018A overflow flag state.
: Not affected
: 1 is set when the result of operation is overflow.
shows concurrent processing instruction.
If overflow does not occur after operation, OV is not reset, and keeps the state before
operation.
: Dyadic
: Branch
: Hardware loop
: Trinomial
: Inter-register transfer
: Immediate data set
: Control
No operation: DPn value does not change.
DPn
DPn
DPn
Example DP0
(n = 0 - 3)
(n = 4 - 7)
Access memory after DPn value is bit-reversed
After memory access, DPn
DPn
DPn+1
DPn–1
DPn + DNn: Adds DN0-DN7 corresponding to DP0-DP7
DPn + imm
DPn = ((DP
DPn = ((DP
DP0 + DN0
L
L
+ DNn )mod (DMX + 1)) + DP
+ DNn )mod (DMY + 1)) + DP
DPn + DNn
Operation
H
H
PD77018A, 77019
25