
1-4
G2 PowerPC Core Reference Manual
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
Overview
— Single-cycle execution for most instructions
— Pipelined FPU for all single-precision and most double-precision operations
Five independent execution units and two register files
— BPU featuring static branch prediction
— A 32-bit IU
— Fully IEEE 754-compliant FPU for both single- and double-precision operations
— LSU for data transfer between data cache and general-purpose registers (GPRs)
and floating-point registers (FPRs)
— SRU that executes condition register (CR), special-purpose register (SPR), and
integer add/compare instructions
— Thirty-two 32-bit GPRs for integer operands
— Thirty-two 64-bit FPRs for single- or double-precision operands
High instruction and data throughput
— Zero-cycle branch capability (branch folding)
— Programmable static branch prediction on unresolved conditional branches
— Instruction fetch unit capable of fetching two instructions per clock from the
instruction cache
— A six-entry instruction queue (IQ) that provides lookahead capability
— Independent pipelines with feed-forwarding that reduces data dependencies in
hardware
— 16-Kbyte data cache and 16-Kbyte instruction cache—four-way set-associative,
physically addressed, LRU replacement algorithm
— Cache write-back or write-through operation programmable on a per page or per
block basis
— BPU that performs CR lookahead operations
— Address translation facilities for 4-Kbyte page size, variable block size, and
256-Mbyte segment size
— A 64-entry, two-way set-associative ITLB and DTLB
— Four-entry data and instruction BAT arrays (for G2 core), and eight-entry data
and instruction BAT arrays (for G2_LE core) providing 128-Kbyte to 256-Mbyte
blocks
— Software table search operations and updates supported through fast trap
mechanism
— 52-bit virtual address; 32-bit physical address
Facilities for enhanced system performance
— A 32- or 64-bit split-transaction data bus interface (60x bus) with burst transfers
F
Freescale Semiconductor, Inc.
n
.