PSD813F1AV-12J データシートの表示（PDF） - STMicroelectronics
部品番号
コンポーネント説明
メーカー
PSD813F1AV-12J Datasheet PDF : 110 Pages
| |||
INSTRUCTIONS
An instruction is defined as a sequence of specific
operations. Each received byte is sequentially de-
coded 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 fol-
lowed exactly. Any invalid combination of instruc-
tion bytes or time-out between two consecutive
bytes while addressing Flash memory will reset
the device logic into READ 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 PSD supports these instructions (see Table
8., page 20):
Flash memory:
■ Erase memory by chip or sector
■ Suspend or resume sector erase
■ Program a Byte
■ Reset to READ mode
■ Read Flash Identifier value
■ Read Sector Protection Status
EEPROM:
■ 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.
PSD813F1V
These instructions are detailed in Table
8., page 20. For efficient decoding of the instruc-
tions, 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. How-
ever, the appropriate sector select signal (FSi or
EESi) must be selected.
Power-down Instruction and Power-up Mode
EEPROM Power Down Instruction. The EE-
PROM can enter power down mode with the help
of the EEPROM power down instruction (see Ta-
ble 8., page 20). Once the EEPROM power down
instruction is decoded, the EEPROM memory can-
not be accessed unless a Return instruction (also
in Table 8., page 20) is decoded. Alternately, this
power down mode will automatically occur when
the APD circuit is triggered (see section entitled
Automatic Power-down (APD) Unit and Power-
down Mode, page 65). Therefore, this instruction
is not required if the APD circuit is used.
Power-up Mode. The PSD internal logic is reset
upon power-up to the READ mode. Any write op-
eration to the EEPROM is inhibited during the first
5ms following power-up. The FSi and EESi select
signals, along with the write strobe signal, must be
in the false state during power-up for maximum se-
curity of the data contents and to remove the pos-
sibility of a byte being written on the first edge of a
write strobe signal. Any write cycle initiation is
locked when VCC is below VLKO.
21/110
Share Link: 