HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 76

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

Single Data Addressing: Among the DSP instructions, the single data transfer instructions
(MOVS.W and MOVS.L) are used to either load data into DSP registers or to store it from them.
With these instructions, the registers R2 to R5 are used as address registers (As) for the single data
transfers.
The four following data addressing instructions exist for single data transfer instructions.
1. Non-updated address registers: The As registers are address pointers. They are not updated.
2. Add index registers: The As registers are address pointers. The Is register values are added to
3. Increment address registers: The As registers are address pointers. The value +2 or +4 is added
4. Decrement address registers: The As registers are address pointers. The value –2 or –4 is added
The address pointer (As) uses the R8 register as an index register (Is).
Figure 2.10 shows the single data transfer addressing.
58
them after the data transfer (post-update).
after the data transfer (post-update).
(+2 or +4 is subtracted) before the data transfer (pre-update).
Note: There are four addressing methods (no update, index register addition (Is),
increment, and decrement). Index register addition and increment are
post-updating methods. Decrement is a pre-updating method.
+2/+4 (INC)
+0 (No update)
–2/–4 (DEC)
Figure 2.10 Single Data Transfer Addressing
31
R8[Is]
ALU
0
31
R2[As]
R3[As]
R4[As]
R5[As]
0
MAB
31
0
CAB