Data Sheet
March 2000
DSP1627 Digital Signal Processor
Lucent Technologies Inc.
37
5 Software Architecture
(continued)
The l in [ ] is an optional argument that specifies the low 16 bits of aT or y.
Add cycles for:
1. When an external memory access is made in X or Y space and wait-states are programmed, add the number of wait-states.
2. If an X space access and a Y space access are made to the same bank of DPRAM in one instruction, add one cycle.
Note:
For transfer statements when loading the upper half of an accumulator, the lower half is cleared if the corre-
sponding CLR bit in the auc register is zero. auc is cleared by reset.
Table 13. Multiply/ALU Instructions
Function Statement
p = x * y
aD = p
aD = aS + p
aD = aS – p
aD = p
aD = aS + p
aD = aS – p
aD = y
aD = aS + y
aD = aS – y
aD = aS & y
aD = aS | y
aD = aS ^ y
aS – y
aS & y
Transfer Statement
y = Y
y = aT
y[l] = Y
aT[l] = Y
x = Y
Y
Y = y[l]
Y = aT[l]
Z:y
Z:y[l]
Z:aT[l]
Cycles (Out/In Cache)
2/1
2/1
1/1
1/1
1/1
1/1
2/2
2/2
2/2
2/2
2/2
x = X
x = X
p = x * y
p = x * y
p = x * y
x = X
Table 14. Replacement Table for Multiply/ALU Instructions
Replace
aD, aS, aT
X
Value
a0, a1
Meaning
One of two DAU accumulators.
X memory space location pointed to by pt. pt is postmodified by +1 and
i, respectively.
RAM location pointed to by rM (M = 0, 1, 2, 3). rM is postmodified by
0, +1, –1, or j, respectively.
Read/Write compound addressing. rM (M = 0, 1, 2, 3) is used twice.
First, postmodified by 0, +1, –1, or j, respectively; and, second, post-
modified by +1, 0, +2, or k, respectively.
*pt++, *pt++i
Y
*rM, *rM++, *rM--, rM++j
Z
*rMzp, *rMpz, *rMm2, *rMjk