MX25L1635D
HardwareProtectedMode(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:
ToexitthehardwareprotectedmoderequiresWP#/SIO2drivinghighoncethehardwareprotectedmodeisentered.Ifthe
WP#/SIO2pinispermanentlyconnectedtohigh,thehardwareprotectedmodecanneverbeentered;onlycanusesoftware
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)ReadDataBytes(READ)
Thereadinstructionisforreadingdataout.TheaddressislatchedonrisingedgeofSCLK,anddatashiftsoutonthefalling
edgeofSCLKatamaximumfrequencyfR.Thefirstaddresscanbeatanylocation.Theaddressisautomaticallyincreased
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 14)
(7)ReadDataBytesatHigherSpeed(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 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
beenreached.
The sequence of issuing FAST_READ instruction is: CS# goes low-> sending FAST_READ instruction code-> 3-byte
address on SI-> 1-dummy byte 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 15)
While Program/Erase/Write Status Register cycle is in progress, FAST_READ instruction is rejected without any impact
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 maximum frequency
fT. The first address 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 instruction. The address counter rolls
overto0whenthehighestaddresshasbeenreached.Oncewriting2READinstruction,thefollowingaddress/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 interleave
on SIO1 & SIO0→4 dummy cycles 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 16 for 2 x I/O Read Mode Timing Waveform).
WhileProgram/Erase/WriteStatusRegistercycleisinprogress, 2READinstructionisrejectedwithoutanyimpactonthe
Program/Erase/Write Status Register current cycle.
P/N:PM1374
REV. 1.5, OCT. 01, 2008
18
Macronix [ MACRONIX INTERNATIONAL ]
