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UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
59 of 808
1.
Introduction
The flash accelerator block in the LPC17xx allows maximization of the performance of the
Cortex-M3 processor when it is running code from flash memory, while also saving power.
The flash accelerator also provides speed and power improvements for data accesses to
the flash memory.
2.
Flash accelerator blocks
The flash accelerator is divided into several functional blocks:
•
AHB-Lite bus interface, accessible by the Cortex-M3 ICode and DCode buses, as well
as by the General Purpose DMA Controller
•
An array of eight 128-bit buffers
•
Flash accelerator control logic, including address compare and flash control
•
A flash memory interface
shows a simplified diagram of the flash accelerator blocks and data paths.
In the following descriptions, the term “fetch” applies to an explicit flash read request from
the CPU. “Prefetch” is used to denote a flash read of instructions beyond the current
processor fetch address.
2.1 Flash memory bank
There is one bank of flash memory controlled by the LPC17xx flash accelerator.
Flash programming operations are not controlled by the flash accelerator, but are handled
as a separate function. A Boot ROM contains flash programming algorithms that may be
called as part of the application program, and a loader that may be run to allow
programming of the flash memory.
UM10360
Chapter 5: LPC17xx Flash accelerator
Rev. 00.06 — 5 June 2009
User manual
Fig 12. Simplified block diagram of the flash accelerator showing potential bus connections
Flash
Accelerator
Control
Flash
Interface
AHB-Lite
bus interface
Buffer
Array
Flash
Memory
Bus
Matrix
DCode
bus
ICode
bus
Cortex-M3
CPU
General
Purpose
DMA
Controller
DMA
Master Port
Combined
AHB
Flash Accelerator