28F200B5, 28F004/400B5, 28F800B5
E
10
PRELIMINARY
28F004B5
BootBlock
40-LeadTSOP
10mmx20mm
TOPVIEW
31
30
29
28
27
26
25
24
23
22
21
32
34
36
37
39
40
20
19
17
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
A
1
A
2
A
3
V
PP
WP#
A
18
RP#
A
16
A
15
A
14
A
13
A
12
A
7
A
6
A
5
A
4
A
8
A
9
A
11
DQ
7
DQ
6
DQ
5
DQ
4
V
CC
CE#
A
0
OE#
GND
DQ
2
DQ
1
DQ
0
V
CC
NC
DQ
3
A
17
GND
NC
A
10
NC
Figure 3. 40-Lead TSOP Pinout Diagram (Available in 4-Mbit Only)
2.3
Memory Blocking Organization
The boot block product family features an
asymmetrically-blocked
system memory integration. Each erase block can
be erased independently of the others up to
100,000 times for commercial temperature or up to
10,000 times for extended temperature. At
automotive temperature, each parameter block can
be erased independently 30,000 times, and each
main and boot block 1,000 times. The block sizes
have been chosen to optimize their functionality for
common applications of nonvolatile storage. The
combination of block sizes in the boot block
architecture allow the integration of several
memories into a single chip. For the address
locations of the blocks, see the memory maps in
Figures 4, 5, 6 and 7.
architecture
providing
2.3.1
ONE 16-KB BOOT BLOCK
The boot block is intended to replace a dedicated
boot PROM in a microprocessor or microcontroller-
based system. The 16-Kbyte (16,384 bytes) boot
block is located at either the top (denoted by -T
suffix) or the bottom (-B suffix) of the address map
to accommodate different microprocessor protocols
for boot code location. This boot block features
hardware controllable write-protection to protect the
crucial microprocessor boot code from accidental
modification. The protection of the boot block is
controlled using a combination of the V
PP
, RP#, and
WP# pins, as is detailed in Section
3.3.
2.3.2
TWO 8-KB PARAMETER BLOCKS
Each boot block component contains two parameter
blocks of 8 Kbytes (8,192 bytes) each to facilitate
storage of frequently updated small parameters that
would normally require an EEPROM. By using
software techniques, the byte-rewrite functionality
of EEPROMs can be emulated. These techniques
are detailed in Intel’s application note,
AP-604
Using Intel’s Boot Block Flash Memory Parameter
Blocks to Replace EEPROM
. The parameter blocks
are not write-protectable.
2.3.3
MAIN BLOCKS - ONE 96-KB +
ADDITIONAL 128-KB BLOCKS
After the allocation of address space to the boot
and parameter blocks, the remainder is divided into
main blocks for data or code storage. Each device
contains one 96-Kbyte (98,304 byte) block and
additional 128-Kbyte (131,072 byte) blocks. The
2-Mbit has one 128-KB block; the 4-Mbit, three; and
the 8-Mbit, seven.