MX25U4035
MX25U8035
Hardware Protected Mode (HPM):
-
When SRWD bit=1, and then WP#/SIO2 is low (or WP#/SIO2 is low before SRWD bit=1), it enters the hardware
protected mode (HPM). The data of the protected area is protected by software protected mode by BP3, BP2,
BP1, BP0 and hardware protected mode by the WP#/SIO2 to against data modification.
Note:
To exit the hardware protected mode requires WP#/SIO2 driving high once the hardware protected mode is entered.
If the WP#/SIO2 pin is permanently connected to high, the hardware protected mode can never be entered; only
can use software protected mode via BP3, BP2, BP1, BP0.
If the system goes into four I/O read mode, the feature of HPM will be disabled.
(6) Read Data Bytes (READ)
The read instruction is for reading data out. The address is latched on rising edge of SCLK, and data shifts out on
the falling edge of SCLK at a maximum frequency fR. The first address byte can be at any location. The address
is automatically increased to the next higher address after each byte data is shifted out, so the whole memory can
be read out at a single READ instruction. The address counter rolls over to 0 when the highest address has been
reached.
The sequence of issuing READ instruction is: CS# goes low→ sending READ instruction code→ 3-byte address on
SI→ data out on SO→ to end READ operation can use CS# to high at any time during data out. (see Figure 15)
(7) Read Data Bytes at Higher Speed (FAST_READ)
The FAST_READ instruction is for quickly reading data out. The address is latched on rising edge of SCLK, and
data of each bit shifts out on the falling edge of SCLK at a maximum frequency fC. The first address byte can be at
any location. The address is automatically increased to the next higher address after each byte data is shifted out,
so the whole memory can be read out at a single FAST_READ instruction. The address counter rolls over to 0 when
the highest address has been reached.
The sequence of issuing FAST_READ instruction is: CS# goes low-> sending FAST_READ instruction code→3-
byte address on SI→1-dummy byte (default) address on SI→data out on SO→ to end FAST_READ operation can
use CS# to high at any time during data out. (see Figure 16)
While Program/Erase/Write Status Register cycle is in progress, FAST_READ instruction is rejected without any im-
pact on the Program/Erase/Write Status Register current cycle.
(8) 2 x I/O Read Mode (2READ)
The 2READ instruction enable double throughput of Serial Flash in read mode. The address is latched on rising
edge of SCLK, and data of every two bits(interleave on 2 I/O pins) shift out on the falling edge of SCLK at a maxi-
mum frequency fT. The first address byte can be at any location. The address is automatically increased to the next
higher address after each byte data is shifted out, so the whole memory can be read out at a single 2READ instruc-
tion. The address counter rolls over to 0 when the highest address has been reached. Once writing 2READ instruc-
tion, the following address/dummy/data out will perform as 2-bit instead of previous 1-bit.
The sequence of issuing 2READ instruction is: CS# goes low sending 2READ instruction 24-bit address inter-
→
→
leave on SIO1 & SIO0 4-bit dummy cycle on SIO1 & SIO0 data out interleave on SIO1 & SIO0 to end 2READ
→
→
→
operation can use CS# to high at any time during data out (see Figure 17 for 2 x I/O Read Mode Timing Waveform).
While Program/Erase/Write Status Register cycle is in progress, 2READ instruction is rejected without any impact
P/N: PM1394
REV. 1.0, MAR. 09, 2009
20
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