MBM29F033C Fujitsu Media Devices, MBM29F033C Datasheet - Page 13

• Manufacturer Part Number: MBM29F033C
• Description: 32M (4M X 8) BIT
• Manufacturer: Fujitsu Media Devices

Write
Sector Group Protection
Device erasure and programming are accomplished via the command register. The contents of the register serve
as inputs to the internal state machine. The state machine outputs dictate the function of the device.
The command register itself does not occupy any addressable memory location. The register is a latch used to
store the commands, along with the address and data information needed to execute the command. The
command register is written by bringing WE to V
the falling edge of WE or CE, whichever happens later; while data is latched on the rising edge of WE or CE,
whichever happens first. Standard microprocessor write timings are used.
Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.
The MBM29F033C features hardware sector group protection. This feature will disable both program and erase
operations in any combination of sixteen sector groups of memory. Each sector group consists of four adjacent
sectors grouped in the following pattern: sectors 0-3, 4-7, 8-11, 12-15, 16-19, 20-23, 24-27, 28-31, 32-35, 36-
39, 40-43, 44-47, 48-51, 52-55, 56-59, and 60-63 (see Table 5). The sector group protection feature is enabled
using programming equipment at the user’s site. The device is shipped with all sector groups unprotected.
To activate this mode, the programming equipment must force V
V
Tables 4 and 5 define the sector address for each of the sixty four (64) individual sectors, and the sector group
address for each of the sixteen (16) individual group sectors. Programming of the protection circuitry begins on
the falling edge of the WE pulse and is terminated with the rising edge of the same. Sector addresses must be
held constant during the WE pulse. Refer to figures 14 and 21 for sector protection waveforms and algorithm.
ID
SGA10
SGA11
SGA12
SGA13
SGA14
SGA15
= 11.5 V), CE = V
SGA0
SGA1
SGA2
SGA3
SGA4
SGA5
SGA6
SGA7
SGA8
SGA9
IL
. The sector addresses (A
A
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
20
Table 5
A
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
20
Sector Group Addresses
21
IL
, while CE is at V
, A
20
, A
19
, and A
A
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
19
ID
MBM29F033C
on address pin A
18
IL
) should be set to the sector to be protected.
and OE is at V
A
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
18
9
IH
and control pin OE, (suggest
. Addresses are latched on
SA12 to SA15
SA16 to SA19
SA20 to SA23
SA24 to SA27
SA28 to SA31
SA32 to SA35
SA36 to SA39
SA40 to SA43
SA44 to SA47
SA48 to SA51
SA52 to SA55
SA56 to SA59
SA60 to SA63
SA0 to SA3
SA4 to SA7
SA8 to SA11
Sectors
-70/-90/-12
13