PSD4235G2-90U STMicroelectronics, PSD4235G2-90U Datasheet - Page 48

• Manufacturer Part Number: PSD4235G2-90U
• Description: IC FLASH 4MBIT 90NS 80TQFP
• Manufacturer: STMicroelectronics

Specifications of PSD4235G2-90U

• Format - Memory: FLASH
• Memory Type: FLASH
• Memory Size: 4M (512K x 8)
• Speed: 90ns
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 80-TQFP, 80-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-1968

Erasing Flash memory
10.2
10.3
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Suspend Sector Erase
When a Sector Erase cycle is in progress, the Suspend Sector Erase instruction can be
used to suspend the cycle by writing 0B0h to any even address when an appropriate Sector
Select (FS0-FS7 or CSBOOT0-CSBOOT3) is high. (See
data from another Flash memory sector after the Erase cycle has been suspended.
Suspend Sector Erase is accepted only during the Flash Sector Erase instruction execution
and defaults to READ mode. A Suspend Sector Erase instruction executed during an Erase
timeout period, in addition to suspending the Erase cycle, terminates the time out period.
The Toggle Flag bit (DQ6/DQ14) stops toggling when the PSD internal logic is suspended.
The status of this bit must be monitored at an address within the Flash memory sector being
erased. The Toggle Flag bit (DQ6/DQ14) stops toggling between 0.1µs and 15 µs after the
Suspend Sector Erase instruction has been executed. The PSD is then automatically set to
READ mode.
If an Suspend Sector Erase instruction was executed, the following rules apply:
●
●
●
●
Resume Sector Erase
If a Suspend Sector Erase instruction was previously executed, the Erase cycle may be
resumed with this instruction. The Resume Sector Erase instruction consists of writing 030h
to any even address while an appropriate Sector Select (FS0-FS7 or CSBOOT0-CSBOOT3)
is high. (See
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 instructions (READ is an operation and is allowed).
If a Reset instruction is received, data in the Flash memory sector that was being
erased is invalid.
Table
29.)
Table
29). This allows reading of
PSD4235G2