LSI Logic Confidential
6-6
Signal Descriptions
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
SDRAM Interface
Between 8 MBytes and 64 MBytes SDRAM or DDR SDRAM can be used, with clock speeds between
80 MHz and 150 MHz. With x32 parts one or two chips may be used, while with x16 parts two or four
chips may be used. SDRAM signals can be configured for either 3.3 V LVTTL for SDR SDRAM or
2.5 V SSTL_2 for DDR SDRAM. SDRAM_CLK, SDRAM_CKE, SDRAM_RAS, SDRAM_CAS,
SDRAM_WE and SDRAM_A timing are specified at 30 pF load. SDRAM_DQM and SDRAM_DQ
timing are specified at 12 pF load.
SDRAM_CLK[1:0]
G20, P20
O
SDRAM clock. These outputs are buffered versions
of the internal clock.
SDRAM_CLK[1:0]
H20, N20
O
Active LOW SDRAM differential clock. Used by DDR
parts.
SDRAM_CKE
C15
O
SDRAM clock enable. This output is used to put the
SDRAMs in low-power mode when the chip is put in
a power-down state.
SDRAM_CAS
B17
O
Active LOW SDRAM Column Address Strobe.
Connects directly to CAS inputs.
SDRAM_RAS
B16
O
Active LOW SDRAM Row Address Strobe.
Connects directly to RAS inputs.
SDRAM_DQM[3:0]
G19, K20, L17,
N17
O
These pins are the byte masks corresponding to
SDRAM_DQ[7:0], [15:8], [23:16] and [31:24]. They
allow for byte reads/writes to SDRAM, and connect
gluelessly to the UDQM/LDQM inputs.
SDRAM_A[15:0]
A18, C20, E18,
E17, F17, C19,
D19, D18, B20,
C18, A20, B18,
C17, A17, B19,
A19
O
SDRAM address, bank select, chip select. These
outputs connect directly to the SDRAM address
inputs, bank address pins, and chip select inputs as
shown in the table below. Bank Address can be two
or three pins, depending on whether there are four
or eight banks:
Table 6.1
DMN-8600 Pin Descriptions (Cont.)
Name
Pin No.
Type
1
Description
Memory
Configuration
Chip Select Pin
Bank Address Pins,
Address Pins
32 MBytes x 2 [15:14]
[13:0]
32 MBytes x 1 [15]
[13:0]
16 MBytes x 2 [15:14]
[13:0]
16 MBytes x 1 [15]
[13:0]
8 MBytes x 2
[15:14]
[12:0]
8 MBytes x 1
[15]
[12:0]
Содержание DMN-8600
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