UPSD33XX Datasheet, PDF (154/231 Pages) STMicroelectronics – Fast 8032 MCU with Programmable Logic

uPSD33xx
Flash Sector Erase. The Sector Erase instruc-
tion sequence uses six WRITE operations, as de-
scribed in Table 80., page 148. Additional Flash
Sector Erase commands to other sectors within
the same Flash array may be issued by the 8032
if the additional commands are sent within a limit-
ed amount of time.
The Erase Time-out Flag Bit (DQ3) reflects the
time-out period allowed between two consecutive
sector erase instruction sequence bytes. If multi-
ple sector erase commands are desired, the addi-
tional sector erase commands (30h) must be sent
by the 8032 to another sector within 80µs after the
previous sector erase command. DQ3 is 0 before
this time period has expired, indicating it is OK to
issue additional sector erase commands. DQ3 will
go to logic ’1’ if the time has been longer than 80µs
since the previous sector erase command (time
has expired), indicating that is not OK to send an-
other sector erase command. In this case, the
8032 must start a new sector erase instruction se-
quence (unlock and command), beginning again
after the current sector erase operation has com-
pleted.
During a Sector Erase operation, the memory sta-
tus may be checked by reading the Error Flag Bit
(DQ5), the Toggle Flag Bit (DQ6), and the Data
Polling Flag Bit (DQ7), as detailed in Reading the
Erase/Program Status Bits, page 149.
During a Sector Erase operation, a Flash memory
accepts only Reset Flash and Suspend Sector
Erase instruction sequences. Erasure of one
Flash memory sector may be suspended, in order
to read data from another Flash memory sector,
and then resumed.
The address provided with the initial Flash Sector
Erase command sequence (Table 80., page 148)
must select the first desired sector (FSx or CS-
BOOTx) to erase. Subsequent sector erase com-
mands that are appended within the time-out
period must be addressed to other desired seg-
ments within the same Flash memory array.
Suspend Sector Erase. When a Sector Erase
operation is in progress, the Suspend Sector
Erase instruction sequence can be used to sus-
pend the operation by writing B0h to any valid ad-
dress within the Flash array that currently is
undergoing an erase operation. This allows read-
ing of data from a different Flash memory sector
within the same array after the Erase operation
has been suspended. Suspend Sector Erase is
accepted only during an Erase operation.
There is up to 15µs delay after the Suspend Sector
Erase command is accepted and the array goes to
Read Array mode. The 8032 will monitor the Tog-
gle Flag Bit (DQ6) to determine when the erase
operation has halted and Read Array mode is ac-
tive.
If a Suspend Sector Erase instruction sequence
was executed, the following rules apply:
– Attempting to read from a Flash memory
sector that was being erased outputs invalid
data.
– Reading from a Flash memory sector that was
not being erased is valid.
– The Flash memory cannot be programmed,
and only responds to Resume Sector Erase
and Reset Flash instruction sequences.
– If a Reset Flash instruction sequence is
received, data in the Flash memory sector that
was being erased is invalid.
Resume Sector Erase. If a Suspend Sector
Erase instruction sequence was previously exe-
cuted, the erase cycle may be resumed with this
instruction sequence. The Resume Sector Erase
instruction sequence consists of writing the com-
mand 30h to any valid address within the Flash ar-
ray that was suspended as shown in Table
80., page 148.
Reset Flash. The Reset Flash instruction se-
quence resets the embedded algorithm running on
the state machine in the targeted Flash memory
(Main or Secondary) and the memory goes into
Read Array mode. The Reset Flash instruction
consists of one bus WRITE cycle as shown in Ta-
ble 80., page 148, and it must be executed after
any error condition that has occurred during a
Flash memory Program or Erase operation.
It may take the Flash memory up to 25µs to com-
plete the Reset cycle. The Reset Flash instruction
sequence is ignored when it is issued during a
Program or Bulk Erase operation. The Reset Flash
instruction sequence aborts any on-going Sector
Erase operation and returns the Flash memory to
Read Array mode within 25µs.
Reset Signal Applied to Flash Memory. When-
ever the PSD Module receives a reset signal from
the MCU Module, any operation that is occurring in
either Flash memory array will be aborted and the
array(s) will go to Read Array mode. It may take up
to 25µs to abort an operation and achieve Read
Array mode.
A reset from the MCU Module will result from any
of these events: an active signal on the uPSD33xx
RESET_IN input pin, a watchdog timer time-out,
detection of low V_CC, or a JTAG debug channel re-
set event.
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