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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
August 2006
Developer’s Manual
Order Number: 306262-004US
187
Intel XScale
®
Processor—Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
3.9.4.5
Saturated Arithmetic Instructions
h
3.9.4.6
Status Register Access Instructions
3.9.4.7
Load/Store Instructions
Table 85.
Multiply Implicit Accumulate Instruction Timings
Mnemonic
Rs Value (Early
Termination)
Minimum Issue
Latency
Minimum Result
Latency
Minimum Resource
Latency
(Throughput)
MIA
Rs[31:15] = 0x0000
or
Rs[31:15] = 0xFFFF
1
1
1
Rs[31:27] = 0x0
or
Rs[31:27] = 0xF
1
2
2
all others
1
3
3
MIAxy
N/A
1
1
1
MIAPH
N/A
1
2
2
Table 86.
Implicit Accumulator Access Instruction Timings
Mnemonic
Minimum Issue Latency
Minimum Result Latency
Minimum Resource
Latency (Throughput)
MAR
2
2
2
MRA
1
(RdLo = 2; RdHi = 3)
2
†
If the next instruction needs to use the result of the MRA for a shift by immediate or as Rn in a
QDADD or QDSUB, one extra cycle of result latency is added to the number listed.
Table 87.
Saturated Data Processing Instruction Timings
Mnemonic
Minimum Issue Latency
Minimum Result Latency
QADD
1
2
QSUB
1
2
QDADD
1
2
QDSUB
1
2
Table 88.
Status Register Access Instruction Timings
Mnemonic
Minimum Issue Latency
Minimum Result Latency
MRS
1
2
MSR
2 (6 if updating mode bits)
1
Table 89.
Load and Store Instruction Timings
Mnemonic
Minimum Issue Latency
Minimum Result Latency
LDR
1
3 for load data; 1 for writeback of base
LDRB
1
3 for load data; 1 for writeback of base
LDRBT
1
3 for load data; 1 for writeback of base
LDRD
1 (+1 if Rd is R12)
3 for Rd; 4 for Rd+1;
1 (+1 if Rd is R12) for write-back of base
LDRH
1
3 for load data; 1 for writeback of base
LDRSB
1
3 for load data; 1 for writeback of base