HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 164

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Carry or Borrow Mode: CS[2:0] = B'000: The DC bit is always cleared to 0.
Negative Value Mode: CS[2:0] = B'001: Bit 31 of the operation result is loaded into the DC bit.
Zero Value Mode: CS[2:0] = B'010: The DC bit is set to1when the operation result is zero;
otherwise it is cleared to 0.
Overflow Mode: CS[2:0] = B'011: The DC bit is always cleared to 0.
Signed Greater Than Mode: CS[2:0] = B'100: The DC bit is always cleared to 0.
Signed Greater Than or Equal Mode: CS[2:0] = B'101: The DC bit is always cleared to 0.
The N bit always indicates the same state as the DC bit set in negative value mode by the CS[2:0]
bits. See the negative value mode part above. The Z bit always indicates the same state as the DC
bit set in zero value mode by the CS[2:0] bits. See the zero value mode part above. The V bit
always indicates the same state as the DC bit set in overflow mode by the CS[2:0] bits. See the
overflow mode part above. The GT bit always indicates the same state as the DC bit set in signed
greater than mode by the CS[2:0] bits. See the signed greater than mode part above.
3.5.7
Fixed-Point Multiply Operation
Figure 3.16 shows the fixed-point multiply operation flow. Table 3.25 shows the variation of this
type of operation and table 3.26 shows the correspondence between each operand and registers.
The multiply operation of the DSP unit is single-word signed single-precision multiplication. The
fixed-point multiply operations are executed in the DSP stage, as shown in figure 3.10. The DSP
stage is the same stage as the MA stage in which memory access is performed.
If a double-precision multiply operation is needed, the CPU double-word multiply instructions can
be made of use.
Rev. 1.00, 02/04, page 126 of 804