psd813f1a-90ut STMicroelectronics, psd813f1a-90ut Datasheet - Page 18

• Manufacturer Part Number: psd813f1a-90ut
• Description: Flash In-system Programmable Isp Peripherals For 8-bit Mcus
• Manufacturer: STMicroelectronics

Preliminary
The
PSD913F1
Functional
Blocks
(cont.)
9.1.1.3.1 Instructions
An instruction is defined as a sequence of specific operations. Each received byte is
sequentially decoded by the PSD and not executed as a standard write operation. The
instruction is executed when the correct number of bytes are properly received and the time
between two consecutive bytes is shorter than the time-out value. Some instructions are
structured to include read operations after the initial write operations.
The sequencing of any instruction must be followed exactly. Any invalid combination of
instruction bytes or time-out between two consecutive bytes while addressing Flash
memory will reset the device logic into a read array mode (Flash memory reads like a ROM
device). An invalid combination or time-out while addressing the EEPROM block will cause
the offending byte to be interpreted as a single operation.
The PSD913F1 supports these instructions (see Table 9):
Flash memory:
EEPROM:
These instructions are detailed in Table 9. For efficient decoding of the instructions, the first
two bytes of an instruction are the coded cycles and are followed by a command byte or
confirmation byte. The coded cycles consist of writing the data AAh to address X555h
during the first cycle and data 55h to address XAAAh during the second cycle. Address
lines A15-A12 are don’t cares during the instruction write cycles. However, the appropriate
sector select signal (FSi or EESi) must be selected.
Erase memory by chip or sector
Suspend or resume sector erase
Program a byte
Reset to read array mode
Read Flash Identifier value
Read sector protection status
Write data to OTP Row
Read data from OTP Row
Power down memory
Enable Software Data Protect (SDP)
Disable SDP
Return from read OTP Row read mode or power down mode.
PSD913F1
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