IXP2400 Intel, IXP2400 Datasheet - Page 15

• Manufacturer Part Number: IXP2400
• Manufacturer: Intel

Specifications of IXP2400

• Operating Supply Voltage (typ): 1.3/1.5/2.5/3.3V
• Mounting: Surface Mount
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Lead Free Status / Rohs Status: Not Compliant

2.3.1.1
2.3.2
2.3.3
2.3.4
2.3.5
Datasheet
Microengine Contexts
There are eight hardware Contexts available in the ME. To allow for efficient context swapping,
each Context has its own register set, Program Counter, and context-specific local registers. Having
a copy per Context eliminates the need to move Context-specific information to/from shared
memory and ME registers for each Context swap. Fast context swapping allows a Context to do
computation while other Contexts wait for IO (typically external memory accesses) to complete or
for a signal from another Context or hardware unit.
General-Purpose Registers (GPRs)
The GPRs are used for general programming purposes. They are read and written exclusively under
program control. GPRs, when used as a source in an instruction, supply operands to the execution
datapath. When used as a destination in an instruction, they are written with the result of the
execution datapath. The specific GPRs selected are encoded in the instruction. The GPRs are
physically and logically contained in two banks, GPR A and GPR B.
Transfer Registers
Transfer Registers (Xfer Registers) are used for transferring data to and from the ME and locations
external to the ME, (for example DRAMs, SRAMs etc). There are four types of transfer registers:
Transfer_In Registers, when used as a source in an instruction, supply operands to the execution
datapath. The specific register selected is either encoded in the instruction, or selected indirectly
via indexing. Transfer_In Registers are written by external units based on the ME requesting data
from a resource outside of itself.
Transfer_Out Registers, when used as a destination in an instruction, are written with the result
from the execution datapath. The specific register selected is encoded in the instruction, or selected
indirectly via indexing. These registers in turn supply data to external units when selected by that
unit.
Next Neighbor Registers
Next Neighbor Registers, when used as a source in an instruction, supply operands to the execution
datapath. They are written either by the adjacent ME or by the same ME they are in. When Next
Neighbor is used as a destination in an instruction; the instruction result data is sent out of the ME
to the adjacent ME.
Local Memory (LM)
Local Memory is addressable storage located in the ME. LM is read and written exclusively under
program control. LM supplies operands to the execution datapath as a source, and receives results
as a destination. The specific LM location selected is based on the value in one of the LM_Addr
Registers which are written by local_CSR_wr instructions. There are two LM_Addr Registers per
1. S_Transfer_In
2. S_Transfer_Out
3. D_Transfer_In
4. D_Transfer_Out
Intel
®
IXP2400 Network Processor
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