Pm29F002
PMC
BLOCK DIAGRAM
ERASE/PROGRAM
VOLTAGE
I/O0-I/O7
GENERATOR
I/O BUFFERS
HIGH VOLTAGE
SWITCH
W E#
COMMAND
REGISTER
DATA
LATCH
SENSE
AMP
CE,OE LOGIC
CE#
OE#
Y-GATING
Y-DECODER
X-DECODER
MEMORY
ARRAY
A0-A17
BOOT BLOCK LOCKOUT DETECTION
DEVICE OPERATION
The state of the Boot Block lockout can be de-
tected by software product identification entry. After
entry, selects Boot Block address with A0 = “0” and A1
= “1” and then read I/O0. A data of “0” means the lock-
out feature is disabled and the Boot Block can be erased
or programmed. A data of “1” means the lockout fea-
ture is enabled and the Boot Block is protected. Prod-
uct identification exit must be executed before the de-
vice returns to read mode.
READ OPERATION
The access of Pm29F002 is similar as that of
EPROM. To obtain data at the outputs, three control
functions must be satisfied:
• CE# is the chip enable and should be pulled low
( VIL ).
• OE# is the output enable and should be pulled
low ( VIL).
• WE# is the write enable and should remains high
( VIH ).
PRODUCT IDENTIFICATION
The product identification mode can be used to identify
the device and the manufacturer by hardware or soft-
ware operation. The hardware operation mode is acti-
vated by applying a 12.0 Volt on A9 pin, typically used
by an external programmer to select the right program-
ming algorithm for the device. For detail, please see
Bus Operation Modes in Table 3. The software opera-
tion mode is activated by three-bus-cycle command.
Please see Software Command Definition in Table 4.
BOOT BLOCK LOCKOUT
The device has a software lockout feature to pre-
vent the data in the boot block from being erased or
reprogrammed. The boot block can be located at the
top or bottom of the address location. The block size is
16 Kbytes. Once the lockout feature is enable, the boot
block can not be erased or reprogrammed. Data in the
main memory block can still be updated through the
regular programming method. The boot block lockout
feature can be turned on by issuing a six-bus-cycle com-
mand sequence. Please refer to Table 4 and Chart 4.
Issue Date: March, 2001 Rev: 1.0
Programmable Microelectronics Corp.
5
PMC [ PMC-SIERRA, INC ]
