PSD913212JIT ST Microelectronics, PSD913212JIT Datasheet - Page 29

• Manufacturer Part Number: PSD913212JIT
• Description: Flash In-System Programmable ISP Peripherals For 8-bit MCUs
• Manufacturer: ST Microelectronics

Preliminary Information
The
PSD9XX
Functional
Blocks
(cont.)
9.1.1.8.3 Flash Erase Suspend Instruction
When a Flash Sector Erase operation is in progress, the Erase Suspend instruction will
suspend the operation by writing 0B0h to any address when an appropriate Chip Select
(FSi or CSBOOTi) is true. (See Table 9). This allows reading of data from another Flash
sector after the Erase operation has been suspended. Erase suspend is accepted only
during the Flash Sector Erase instruction execution and defaults to read array mode. An
Erase Suspend instruction executed during an Erase timeout will, in addition to suspending
the erase, terminate the time out.
The Toggle Bit DQ6 stops toggling when the PSD9XX internal logic is suspended. The
toggle Bit status must be monitored at an address within the Flash sector being erased.
The Toggle Bit will stop toggling between 0.1 µs and 15 µs after the Erase Suspend
instruction has been executed. The PSD9XX will then automatically be set to Read Flash
Block Memory Array mode.
If an Erase Suspend instruction was executed, the following rules apply:
9.1.1.8.4 Flash Erase Resume Instruction
If an Erase Suspend instruction was previously executed, the erase operation may be
resumed by this instruction. The Erase Resume instruction consists of writing 030h to any
address while an appropriate Chip Select (FSi or CSBOOTi) is true. (See Table 9.)
9.1.1.9 Specific Features
9.1.1.9.1 Flash and Secondary Flash Sector Protect
Each Flash and Secondary Flash sector can be separately protected against Program and
Erase functions. Sector Protection provides additional data security because it disables all
program or erase operations. This mode can be activated through the JTAG Port or a
Device Programmer.
Sector protection can be selected for each sector using the PSDsoft Configuration
program. This will automatically protect selected sectors when the device is programmed
through the JTAG Port or a Device Programmer. Flash sectors can be unprotected to
allow updating of their contents using the JTAG Port or a Device Programmer. The
microcontroller can read (but cannot change) the sector protection bits.
Any attempt to program or erase a protected Flash sector will be ignored by the device.
The Verify operation will result in a read of the protected data. This allows a guarantee of
the retention of the Protection status.
The sector protection status can be read by the MCU through the Flash protection and
Secondary Flash protection registers (CSIOP). See Table 11.
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Attempting to read from a Flash sector that was being erased will output invalid data.
Reading from a Flash sector that was not being erased is valid.
The Flash memory cannot be programmed, and will only respond to Erase Resume
and Reset instructions (read is an operation and is OK).
If a Reset instruction is received, data in the Flash sector that was being erased will
be invalid.
PSD9XX Family
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