3.3V Uniform Sector
Dual and Quad Serial Flash
GD25Q80C
7.31. Enable Reset (66H) and Reset (99H)
If the Reset command is accepted, any on-going internal operation will be terminated and the device will return to its
default power-on state and lose all the current volatile settings, such as Volatile Status Register bits, Write Enable Latch
status (WEL), Program/Erase Suspend status, Read Parameter setting (P7-P0), Continuous Read Mode bit setting (M7-
M0) and Wrap Bit Setting (W6-W4).
The “Reset (99H)” command sequence as follow: CS# goes low Sending Enable Reset command CS# goes
high CS# goes low Sending Reset command CS# goes high. Once the Reset command is accepted by the device,
the device will take approximately tRST_R to reset. During this period, no command will be accepted. Data corruption may
happen if there is an on-going or suspended internal Erase or Program operation when Reset command sequence is
accepted by the device. It is recommended to check the BUSY bit and the SUS bit in Status Register before issuing the
Reset command sequence.
Figure 34. Enable Reset and Reset command Sequence Diagram
CS#
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6 7
SCLK
SI
Command
66H
Command
99H
High-Z
SO
7.32. Read Serial Flash Discoverable Parameter (5AH)
The Serial Flash Discoverable Parameter (SFDP) standard provides a consistent method of describing the functional
and feature capabilities of serial flash devices in a standard set of internal parameter tables. These parameter tables can
be interrogated by host system software to enable adjustments needed to accommodate divergent features from multiple
vendors. The concept is similar to the one found in the Introduction of JEDEC Standard, JESD68 on CFI. SFDP is a standard
of JEDEC Standard No.216.
Figure 35. Read Serial Flash Discoverable Parameter command Sequence Diagram
CS#
0
1
2
3
4
5
6
7
8
9 10
28 29 30 31
SCLK
SI
Command
5AH
24-bit address
23 22 21
3
2
1
0
High-Z
SO
CS#
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Dummy Byte
SCLK
SI
7
6
5
4
3
2
1
0
Data Out1
Data Out2
SO
7
6
5
4
3
2
1
0
7
6
5
MSB
MSB
36
GILWAY [ GILWAY TECHNICAL LAMP ]
