LSI LSI53C1030, Technical Manual

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2-26 Functional Description
Version 2.1 Copyright © 2001, 2002, 2003 by LSI Logic Corporation. All rights reserved.
2.5.2 NVSRAM Interface
Write journaling for IM requires an NVSRAM. The LSI53C1030 Fusion-
MPT firmware is capable of maintaining a second disk as a mirror of the
boot drive. To do so, the LSI Logic Fusion-MPT firmware writes to both
the boot drive and the mirror drive. The mirroring of the boot drive is
transparent to the BIOS, drivers, and operating system.
Figure 2.5
provides a block diagram illustrating how to connect the NVSRAM. This
design employs the CPLD to latch the address instead of using separate
address latches.
When using an NVSRAM, pull the MAD[3] Power-On Sense pin HIGH
during board boot-up. This configures the external memory interface as
an NVSRAM interface. During operation, RAMCE/ selects the NVSRAM
when MAD[3] is pulled HIGH.
Table 2.4 Flash Signature Value
Flash Address Flash Signature Values
Bytes [3:0] 0xEA XX XX XX
Bytes [7:4] 0x5A 0xEA 0xA5 0x5A
Bytes [11:8] 0xA5 0x5A 0xEA 0xA5
Bytes [15:12] 0x5A 0xA5 0x5A 0xEA