PowerPC 740 and PowerPC 750 Embedded Microprocessor
IBM CMOS 0.20 um Copper Technology EMPPC740L and EMPPC750L
Features
This section summarizes features of the implementation of the PowerPC 750 architecture. Major features are
as follows.
• Branch processing unit
- Four instructions fetched per clock.
- One branch processed per cycle (plus resolving 2 speculations).
- Up to 1 speculative stream in execution, 1 additional speculative stream in fetch.
- 512-entry branch history table (BHT) for dynamic prediction.
- 64-entry, 4-way set associative branch target instruction cache (BTIC) for eliminating branch delay
slots.
• Dispatch unit
- Full hardware detection of dependencies (resolved in the execution units).
- Dispatch two instructions to six independent units (system, branch, load/store, fixed-point unit 1,
fixed-point unit 2, or floating-point).
- Serialization control (predispatch, postdispatch, execution, serialization).
• Decode
- Register file access.
- Forwarding control.
- Partial instruction decode.
• Load/store unit
- One cycle load or store cache access (byte, half-word, word, double-word).
- Effective address generation.
- Hits under misses (one outstanding miss).
- Single-cycle misaligned access within double word boundary.
- Alignment, zero padding, sign extend for integer register file.
- Floating-point internal format conversion (alignment, normalization).
- Sequencing for load/store multiples and string operations.
- Store gathering.
- Cache and TLB instructions.
- Big and little-endian byte addressing supported.
- Misaligned little-endian support in hardware.
• Fixed-point units
- Fixed-point unit 1 (FXU1); multiply, divide, shift, rotate, arithmetic, logical.
- Fixed-point unit 2 (FXU2); shift, rotate, arithmetic, logical.
- Single-cycle arithmetic, shift, rotate, logical.
- Multiply and divide support (multi-cycle).
- Early out multiply.
5/20/99
Version 1.51
PowerPC 740 and PowerPC 750 Datasheet
Page 3
IBM [ IBM ]
