GT-64260A Design Guide
Doc. No. MV-S300165-00, Rev. A
CONFIDENTIAL
Copyright © 2002 Marvell
Page 58
Document Classification: Proprietary Information
May 21, 2002, Preliminary
6.5
Signals Timing
Note
For more information on device bus signals, see the GT-64260A datasheet’s "Pin Information" section.
The GT-64260A provides programmable access timing for various device implementations. The programmable
parameters for device access have a 1 clock cycle granularity and are set per CS* (bank). All programmable
access timings are set in the corresponding Device Bank Parameters register (Offsets: 0x45c, 0x460, 0x464,
0x468). There are separate parameters for write and read accesses, the read access parameters include TurnOff,
Acc2First, Acc2Next, and BAdrSkew. The write parameters include ALE2Wr, WrLow and WrHigh.
shows a device burst read example with the following device timing parameters.
•
Acc2First = 5 cycles.
•
Acc2Next = 3 cycles.
•
BadrSkew = 0 cycles.
Figure 24: Device Burst Read Example
shows a device burst write example with the following device timing parameters:
•
ALE2Wr = 5 cycles.
•
WrLow = 1 cycles.
•
WrHigh = 3 cycles.
ALE
CSTiming*
AD[31:0]
BAdr[2:0]
DevRW*
Wr*
Device_addr[26:3]
D0
B1
D1
Address
DBDLast*
B0
D2
B2
Burst
Last
1clk
1clk
1clk
1clk
Acc2First
Acc2Next
Acc2Next
Acc2Next
Tlatch
1
D3
B3
Address
Notes:
Tlatch1 depends on the latch device, such as a discrete device (e.g.,
74373) or PLD.