V29C51000T-90J Просмотр технического описания (PDF) - Mosel Vitelic, Corp
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V29C51000T-90J Datasheet PDF : 16 Pages
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MOSEL VITELIC
V29C51000T/V29C51000B
Functional Description
The V29C51000T/V29C51000B consists of 256
equally-sized sectors of 512 bytes each. The 8 KB
lockable Boot Block is intended for storage of the
system BIOS boot code. The boot code is the first
piece of code executed each time the system is
powered on or rebooted.
The V29C51000 is available in two versions: the
V29C51000T with the Boot Block address starting
from E000H to FFFFH, and the V29C51000B with
the Boot Block address starting from 0000H to
FFFFH.
Read Cycle
A read cycle is performed by holding both CE
and OE signals LOW. Data Out becomes valid only
when these conditions are met. During a read cycle
WE must be HIGH prior to CE and OE going LOW.
WE must remain HIGH during the read operation
for the read to complete (see Table 1).
Output Disable
Returning OE or CE HIGH, whichever occurs first
will terminate the read operation and place the l/O
pins in the HIGH-Z state.
Standby
The device will enter standby mode when the CE
signal is HIGH. The l/O pins are placed in the
HIGH-Z, independent of the OE signal.
Command Sequence
The V29C51000T/V29C51000B does not
provide the “reset” feature to return the chip to its
normal state when an incomplete command
sequence or an interruption has happened. In this
case, normal operation (Read Mode) can be
restored by issuing a “non-existent” command
sequence, for example Address: 5555H, Data FFH.
Table 1. Operation Modes Decoding
V29C51000T
8KB Boot Block
512
FFFFH
E000H
512
V29C51000B
512
512
512
1FFFH
512
8KB Boot Block
0000H
0000H
51000-13
8KB Boot Block = 16 Sectors
Byte Program Cycle
The V29C51000T/V29C51000B is programmed
on a byte-by-byte basis. The byte program
operation is initiated by using a specific four-bus-
cycle sequence: two unlock program cycles, a
program setup command and program data
program cycles (see Table 2).
During the byte program cycle, addresses are
latched on the falling edge of either CE or WE,
whichever is last. Data is latched on the rising edge
of CE or WE, whichever is first. The byte program
cycle can be CE controlled or WE controlled.
Sector Erase Cycle
The V29C51000T/V29C51000B features a
sector erase operation which allows each sector to
be erased and reprogrammed without affecting
data stored in other sectors. Sector erase operation
is initiated by using a specific six-bus-cycle
sequence: Two unlock program cycles, a setup
command, two additional unlock program cycles,
and the sector erase command (see Table 2). A
sector must be first erased before it can be
reprogrammed. While in the internal erase mode,
Decoding Mode
CE
OE
WE
A0
A1
A9
I/O
Read
VIL
VIL
VIH
A0
A1
A9
READ
Program
VIL
VIH
VIL
A0
A1
A9
PD
Standby
VIH
X
X
X
X
X
HIGH-Z
Autoselect Device ID
VIL
VIL
VIH
VIH
VIL
VH
CODE
Autoselect Manufacture ID
VIL
VIL
VIH
VIL
VIL
VH
CODE
Output Disable
VIL
VIH
VIH
X
X
X
HIGH-Z
NOTES:
1. X = Don’t Care, VIH = HIGH, VIL = LOW.
2. PD: The data at the byte address to be programmed.
V29C51000T/V29C51000B Rev. 0.5 October 2000
9
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