qh25f320s33b8 Numonyx, qh25f320s33b8 Datasheet - Page 27

• Manufacturer Part Number: qh25f320s33b8
• Description: Numonyx? Serial Flash Memory S33
• Manufacturer: Numonyx

Numonyx™ Serial Flash Memory (S33)
8.2.3
8.2.4
8.2.5
8.2.6
December 2007
Order Number: 314822-03
As with any command that writes to the device or changes the memory contents, the
Write Enable command must be executed prior to the Page Program command in order
to set the WEL bit. If the WEL bit is not set, the Page Program command will be
ignored.
If the WEL bit is set and the address is protected, the program operation will not occur.
Instead, the P_FAIL flag of the Status Register will set and the WEL bit will clear.
The Page Program command can be botched (cancelled) by failing to raise the S# edge
on a whole-byte increment. The following occur if the Page Program command is
botched:
Assuming the WEL bit is set, the address is unprotected, and the command is not
botched, the rising edge of S# initiates the program operation. This program operation
cannot be terminated without powering off the device, and doing so will result in
unexpected data.
Read Data Bytes Command (03h)
The Read Data Bytes command requires a 3-byte address. After the last address byte is
clocked in (on the rising clock edge), the first data bit is clocked out on the subsequent
falling clock edge. Data clocks out continuously and sequentially as long as S# remains
low. When the address reaches its maximum, it wraps back to zero. The Read Data
Byte command supports up to 33.3 MHz.
Write Disable Command (04h)
The Write Disable command clears the WEL bit, which corresponds to bit SR1. Clearing
the WEL bit disables the following commands:
These commands can be re-enabled by executing the Write Enable command as
described in
Read SPI SR Command (05h)
The Read SR command continuously polls the SPI Status Register. As long as S#
remains low, a refreshed version of the status register is continuously clocked out. The
Read SR command does not require address bytes, data bytes or dummy bytes.
Write Enable Command (06h)
The Write Enable command sets the WEL bit, which corresponds to bit SR1. Setting the
WEL bit enables the following commands:
• The WEL bit will not be cleared.
• SR Fail Flags (described in
• None of the bytes written into the program buffer will be programmed into the flash
• Write SR
• Page Program
• OTP Program
• Bulk Erase
• Parameter Block Erase
• Sector Erase
• Write SR
array.
Section
8.2.6. The WEL bit is cleared at power-up.
Table
16) will not be set.
Datasheet
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