BRIGHT
Microelectronics
Inc.
Preliminary BM29F400T/BM29F400B
APPENDIX A:
Compatibility to AMD's AMD29F400B:
The device is essentially fully functional compatible to the AMD29F400B except for three issues:
1. During Erase Suspend
2. DQ2 Status Flag
3. Command Address Subset
During Erase Suspend, the device can only read data in the memory-- not Program or execute an
Auto Command like the AMD29400B. Also, the DQ2 Flag is not available. This flag is used to
determine during multiple or single sector erase whether a sector has been selected for erase. DQ2
can only be used during and embedded sector erase operation or during erase suspend.
In the AMD device, commands do not require address pin A15, A14, A13, A12, A11 to be forced
during the command sequence. This makes their device slighly easier to inadvertently create a
command and cause a program, erase or malfunction. The advantage of reducing the address to a
subset is to simplify the hardware interface in systems where control signals are limited in number.
The 29F400B reduces the interface requirement by 4 signals. However if the full address is supplied
(i.e.2AAAH and 5555H) by the host system, there will be no incompatibility using either device.
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