lpc2470fet208 NXP Semiconductors, lpc2470fet208 Datasheet - Page 26

• Manufacturer Part Number: lpc2470fet208
• Description: Flashless 16-bit/32-bit Micro; Ethernet, Can, Lcd, Usb 2.0 Device/host/otg, External Memory Interface
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC2470_0
Preliminary data sheet
7.2 On-chip SRAM
7.3 Memory map
Pipeline techniques are employed so that all parts of the processing and memory systems
can operate continuously. Typically, while one instruction is being executed, its successor
is being decoded, and a third instruction is being fetched from memory.
The ARM7TDMI-S processor also employs a unique architectural strategy known as
Thumb, which makes it ideally suited to high-volume applications with memory
restrictions, or applications where code density is an issue.
The key idea behind Thumb is that of a super-reduced instruction set. Essentially, the
ARM7TDMI-S processor has two instruction sets:
The Thumb set’s 16-bit instruction length allows it to approach higher density compared to
standard ARM code while retaining most of the ARM’s performance.
The LPC2470 includes a SRAM memory of 64 kB reserved for the ARM processor
exclusive use. This RAM may be used for code and/or data storage and may be accessed
as 8 bits, 16 bits, and 32 bits.
A 16 kB SRAM block serving as a buffer for the Ethernet controller and a 16 kB SRAM
associated with the second AHB bus can be used both for data and code storage, too.
The 2 kB RTC SRAM can be used for data storage only. The RTC SRAM is battery
powered and retains the content in the absence of the main power supply.
The LPC2470 memory map incorporates several distinct regions as shown in
Figure
In addition, the CPU interrupt vectors may be remapped to allow them to reside in either
boot ROM or SRAM (see
Table 5.
Address range General use
0x0000 0000 to
0x3FFF FFFF
0x4000 0000 to
0x7FFF FFFF
•
•
the standard 32-bit ARM set
a 16-bit Thumb set
4.
LPC2470 memory usage and details
On-chip RAM
Fast I/O
Rev. 00.01 — 5 October 2007
Section
7.26.6).
Address range details and description
0x3FFF C000 - 0x3FFF FFFF
0x4000 0000 - 0x4000 FFFF
0x7FE0 0000 - 0x7FE0 3FFF
0x7FD0 0000 - 0x7FD0 3FFF
Fast communication chip
Fast GPIO registers
RAM (64 kB)
Ethernet RAM (16 kB)
USB RAM (16 kB)
LPC2470
© NXP B.V. 2007. All rights reserved.
Table 5
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