xref: /aosp_15_r20/external/flashrom/doc/user_docs/msi_jspi1.rst (revision 0d6140be3aa665ecc836e8907834fcd3e3b018fc)
1*0d6140beSAndroid Build Coastguard Worker=========
2*0d6140beSAndroid Build Coastguard WorkerMSI JSPI1
3*0d6140beSAndroid Build Coastguard Worker=========
4*0d6140beSAndroid Build Coastguard Worker
5*0d6140beSAndroid Build Coastguard WorkerJSPI1 is a 5x2 or 6x2 2.0mm pitch pin header on many MSI motherboards.
6*0d6140beSAndroid Build Coastguard WorkerIt is used to recover from bad boot ROM images. Specifically,
7*0d6140beSAndroid Build Coastguard Workerit appears to be used to connect an alternate ROM with a working image.
8*0d6140beSAndroid Build Coastguard WorkerPull the #HOLD line low to deselect the onboard SPI ROM, allowing another
9*0d6140beSAndroid Build Coastguard WorkerSPI ROM to take its place on the bus. Pull the #WP line high to disable write-protection.
10*0d6140beSAndroid Build Coastguard WorkerSome boards use 1.8V flash chips, while others use 3.3V flash chips;
11*0d6140beSAndroid Build Coastguard WorkerCheck the flash chip datasheet to determine the correct value.
12*0d6140beSAndroid Build Coastguard Worker
13*0d6140beSAndroid Build Coastguard Worker**JSPI1 (5x2)**
14*0d6140beSAndroid Build Coastguard Worker
15*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ====
16*0d6140beSAndroid Build Coastguard Workername     pin      pin      name
17*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ====
18*0d6140beSAndroid Build Coastguard WorkerVCC      1        2 	   VCC
19*0d6140beSAndroid Build Coastguard WorkerMISO     3        4	   MOSI
20*0d6140beSAndroid Build Coastguard Worker#SS      5        6	   SCLK
21*0d6140beSAndroid Build Coastguard WorkerGND      7        8	   GND
22*0d6140beSAndroid Build Coastguard Worker#HOLD    9        10 	   NC
23*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ====
24*0d6140beSAndroid Build Coastguard Worker
25*0d6140beSAndroid Build Coastguard Worker**JSPI1 (6x2)**
26*0d6140beSAndroid Build Coastguard Worker
27*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ============
28*0d6140beSAndroid Build Coastguard Workername     pin      pin      name
29*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ============
30*0d6140beSAndroid Build Coastguard WorkerVCC      1	  2	   VCC
31*0d6140beSAndroid Build Coastguard WorkerSO       3        4	   SI
32*0d6140beSAndroid Build Coastguard Worker#SS      5	  6	   CLK
33*0d6140beSAndroid Build Coastguard WorkerGND      7        8	   GND
34*0d6140beSAndroid Build Coastguard WorkerNC       9        10	   NC (no pin)
35*0d6140beSAndroid Build Coastguard Worker#WP      11       12	   #HOLD
36*0d6140beSAndroid Build Coastguard Worker======== ======== ======== ============
37*0d6140beSAndroid Build Coastguard Worker
38*0d6140beSAndroid Build Coastguard Worker======== =====================================
39*0d6140beSAndroid Build Coastguard Workername	 function
40*0d6140beSAndroid Build Coastguard Worker======== =====================================
41*0d6140beSAndroid Build Coastguard WorkerVCC	 Voltage (See flash chip datasheet)
42*0d6140beSAndroid Build Coastguard WorkerMISO	 SPI Master In/Slave Out
43*0d6140beSAndroid Build Coastguard WorkerMOSI	 SPI Master Out/Slave In
44*0d6140beSAndroid Build Coastguard Worker#SS	 SPI Slave (Chip) Select (active low)
45*0d6140beSAndroid Build Coastguard WorkerSCLK	 SPI Clock
46*0d6140beSAndroid Build Coastguard WorkerGND	 ground/common
47*0d6140beSAndroid Build Coastguard Worker#HOLD	 SPI hold (active low)
48*0d6140beSAndroid Build Coastguard Worker#WP	 SPI write-protect (active low)
49*0d6140beSAndroid Build Coastguard WorkerNC	 Not Connected (or no pin)
50*0d6140beSAndroid Build Coastguard Worker======== =====================================
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