MPC8540 datasheet(223/1302 Pages) FREESCALE

223 / 1302 page

Features

MPC8540 PowerQUICC III Integrated Host Processor Reference Manual, Rev. 1

Freescale Semiconductor

5-9

Figure 5-3. Three-Stage Load/Store Unit

The LSU has the following features:

— 3-cycle load latency

— Fully pipelined

— The load miss queue allows up to four load misses before stalling.

— Load hits can continue to be serviced when the load miss queue is full.

— Seven-entry L1 store queue allows full pipelining of stores

— The three-entry data line fill buffer is used for loads and cacheable stores. Stores are

allocated here so loads can access data from the store immediately.

— The data write buffer contains three entries: one dedicated for snoop pushes, one

dedicated for cast outs, and one that can be used for snoop pushes or cast outs.

•

Cache coherency

— Supports four-state cache coherency: modified-exclusive, exclusive, shared, and invalid

(MESI)

— Bus support for hardware-enforced coherency (bus snooping)

•

Core complex bus (CCB)—internal bus

— High-speed, on-chip local bus with data tagging

— 32-bit address bus

— Address protocol with address pipelining and retry/copyback derived from bus used by

previous generations of PowerPC processors (referred to as the 60x bus)

— Two general-purpose read data buses and one write data bus

Reservation

Station

Load/Store Unit

(64-/32-Bit)

Load

Data Line

Fill Buffer

Data Write

Buffer

L1 Store

Queue

Miss

Queue

To Core Interface Unit

To data cache

To GPR operand bus

To completion queue

To GPRs

Three-Stage Pipeline

Queues and Buffers

MPC8540 Datasheet(PDF) 223 Page - Freescale Semiconductor, Inc

MPC8540 Datasheet(HTML) 223 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL