里面有sdram的时序
em638325引脚图：
Overview
The EM638325 SDRAM is a high-speed CMOS synchronous DRAM containing 64 Mbits. It is internally configured
as a quad 512K x 32 DRAM with a synchronous interface (all signals are registered on the positive edge of the clock
signal, CLK). Each of the 512K x 32 bit banks is organized as 2048 rows by 256 columns by 32 bits. Read and write
accesses to the SDRAM are burst oriented; accesses start at a selected location and continue for a programmed number
of locations in a programmed sequence. Accesses begin with the registration of a BankActivate command which is then
followed by a Read or Write command.
The EM638325 provides for programmable Read or Write burst lengths of 1, 2, 4, 8, or full page, with a burst
termination option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at
the end of the burst sequence. The refresh functions, either Auto or Self Refresh are easy to use.
By having a programmable mode register, the system can choose the most suitable modes to maximize its
performance. These devices are well suited for applications requiring high memory bandwidth.
Features
· Clock rate: 200/183/166/143/125/100 MHz
· Fully synchronous operation
· Internal pipelined architecture
· Four internal banks (512K x 32bit x 4bank)
· Programmable Mode
- CAS# Latency: 2 or 3
- Burst Length: 1, 2, 4, 8, or full page
- Burst Type: interleaved or linear burst
- Burst-Read-Single-Write
· Burst stop function
· Individual byte controlled by DQM0-3
· Auto Refresh and Self Refresh
· 4096 refresh cycles/64ms
· Single +3.3V ± 0.3V power supply
· Interface: LVTTL
· Package: 400 x 875 mil, 86 Pin TSOP II, 0.50mm
pin pitch
· Lead Free Package available
完整的pdf格式文档51黑下载地址：
datasheet.pdf
(781.1 KB, 下载次数: 4)
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