SH7727 Datasheet, PDF (110/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 2 CPU
2.2 Data Format
2.2.1 Data Format in Registers (Non-DSP Type)
Register operands are always longwords (32 bits) (figure 2.9). When the memory operand is only
a byte (8 bits) or a word (16 bits), it is sign-extended into a longword when loaded into a register.
31
0
Longword
Figure 2.9 Longword Operand
2.2.2 DSP-Type Data Format
The SH7727 has several different data formats that depend on operations. This section explains
the data formats for DSP type instructions.
Figure 2.10 shows three DSP-type data formats with different binary point positions. A CPU-type
data format with the binary point to the right of bit 0 is also shown for reference.
The DSP-type fixed point data format has the binary point between bit 31 and bit 30. The DSP-
type integer format has the binary point between bit 16 and bit 15. The DSP-type logical format
does not have a binary point. The valid data lengths of the data formats depend on the operations
and the DSP registers.
Rev. 5.00 Dec 12, 2005 page 38 of 1034
REJ09B0254-0500