M29W400 ST Microelectronics, M29W400 Datasheet - Page 4

• Manufacturer Part Number: M29W400
• Description: 4 Mbit 512Kb x8 or 256Kb x16 / Boot Block Low Voltage Single Supply Flash Memory
• Manufacturer: ST Microelectronics

M29W400T, M29W400B
Figure 3. Memory Map and Block Address Table (x8)
Organisation
The M29W400 is organised as 512K x8 or 256K
x16 bits selectable by the BYTE signal. When
BYTE is Low the Byte-wide x8 organisation is
selected and the address lines are DQ15A–1 and
A0-A17. The Data Input/Output signal DQ15A–1
acts as address line A–1 which selects the lower or
upper Byte of the memory word for output on
DQ0-DQ7, DQ8-DQ14 remain at High impedance.
When BYTE is High the memory uses the address
inputs A0-A17 and the Data Input/Outputs DQ0-
DQ15. Memory control is provided by Chip Enable
E, Output Enable G and Write Enable W inputs.
A Reset/Block Temporary Unprotection RP tri-level
input provides a hardware reset when pulled Low,
and when held High (at V
blocks previously protected allowing them to be
programed and erased. Erase and Programopera-
tions are controlled by an internal Program/Erase
Controller (P/E.C.). Status Register data output on
DQ7 provides a Data Polling signal, and DQ6 and
DQ2 provide Toggle signals to indicate the state of
the P/E.C operations. A Ready/Busy RB output
indicates the completion of the internal algorithms.
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7BFFFh
7FFFFh
6FFFFh
5FFFFh
4FFFFh
3FFFFh
2FFFFh
1FFFFh
0FFFFh
7C000h
7A000h
79FFFh
77FFFh
78000h
70000h
60000h
50000h
40000h
30000h
20000h
10000h
00000h
8K PARAMETER BLOCK
8K PARAMETER BLOCK
ID
) temporarily unprotects
16K BOOT BLOCK
32K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
M29W400T
Memory Blocks
The devices feature asymmetrically blocked archi-
tecture providing system memory integration. Both
M29W400Tand M29W400Bdevices have an array
of 11 blocks, one Boot Block of 16 KBytes or 8
KWords, two Parameter Blocks of 8 KBytes or 4
KWords, one Main Block of 32 KBytes or 16
KWords and seven Main Blocks of 64 KBytes or 32
KWords. The M29W400T has the Boot Block at the
top of the memory address space and the
M29W400B locates the Boot Block starting at the
bottom. The memory maps are showed in Figure
3. Each block can be erased separately, any com-
bination of blocks can be specified for multi-block
erase or the entire chip may be erased. The Erase
operations are managed automatically by the
P/E.C. The block erase operation can be sus-
pended in order to read from or program to any
block not being ersased, and then resumed.
Block protection provides additional data security.
Each block can be separately protected or unpro-
tected against Program or Erase on programming
equipment. All previously protected blocks can be
temporarily unprotected in the application.
7FFFFh
6FFFFh
5FFFFh
4FFFFh
3FFFFh
2FFFFh
1FFFFh
0FFFFh
07FFFh
05FFFh
03FFFh
70000h
60000h
50000h
40000h
30000h
20000h
10000h
08000h
06000h
04000h
00000h
8K PARAMETER BLOCK
8K PARAMETER BLOCK
16K BOOT BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
64K MAIN BLOCK
32K MAIN BLOCK
M29W400B
AI02090