Alu Integer Operations; Figure 3.6 Alu Integer Arithmetic Operation Flow; Table 3.3 Variation Of Alu Integer Operations - Renesas HD6417641 Hardware Manual

Section 3 DSP Operation
3.1.2

ALU Integer Operations

Figure 3.6 shows the ALU integer arithmetic operation flow. Table 3.3 shows the variation of this
type of operation. The correspondence between each operand and registers is the same as ALU
fixed-point operations as shown in table 3.2.
39
Guard
Ignored
Cleared
Table 3.3 Variation of ALU Integer Operations
Mnemonic Function
PINC Increment by 1
PDEC Decrement by 1
Note: The ALU integer operations are basically 24-bit operation, the upper 16 bits of the base
precision and 8 bits of the guard bits parts. So the signed bit is copied to the guard-bit parts
when a register not providing the guard-bit parts is specified as the source operand. When
a register not providing the guard-bit parts is specified as a destination operand, the upper
word excluding the guard bits of the operation result are input into the destination register.
Rev. 4.00 Sep. 14, 2005 Page 104 of 982
REJ09B0023-0400
31
Source 1
Guard Destination
39 31

Figure 3.6 ALU Integer Arithmetic Operation Flow

0 39 31
Source 2
Guard
ALU
0
Source 1 Source 2
+1
Sx
+1
Sy
−1
Sx
−1
Sy
0
GT Z N V DC
DSR
Destination
Dz
Dz
Dz
Dz