MSI JSPI1: Difference between revisions

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JSPI1 is a 5×2 or 6x2 2.0mm pitch pin header on many MSI motherboards.
JSPI1 is a 5x2 or 6x2 2.0mm pitch pin header on many MSI motherboards.
It is used to recover from bad boot ROM images.  Specifically, it appears to be used to connect an alternate ROM with a working image. Pull the #HOLD line low to deselect the onboard SPI ROM, allowing another SPI ROM to take its place on the bus. Pull the #WP line high to disable write-protection.
It is used to recover from bad boot ROM images.  Specifically, it appears to be used to connect an alternate ROM with a working image. Pull the #HOLD line low to deselect the onboard SPI ROM, allowing another SPI ROM to take its place on the bus. Pull the #WP line high to disable write-protection. Some boards use 1.8V flash chips, while others use 3.3V flash chips; Check the flash chip datasheet to determine the correct value.


{| class="wikitable"
{| class="wikitable"
Line 6: Line 6:
!name!!pin!!pin!!name
!name!!pin!!pin!!name
|-
|-
|3VSB||1||2||3VSB
|VCC||1||2||VCC
|-
|-
|MISO||3||4||MOSI
|MISO||3||4||MOSI
Line 21: Line 21:
!name!!pin!!pin!!name
!name!!pin!!pin!!name
|-
|-
|#HOLD||1||2||#WP
|VCC||1||2||VCC
|-
|-
|NC||3||4||NC
|SO||3||4||SI
|-
|-
|NC||5||6||GND
|#SS||5||6||CLK
|-
|-
|CLK||7||8||#SS
|GND||7||8||GND
|-
|-
|SI||9||10||SO
|NC||9||10||NC (no pin)
|-
|-
|NC||11||12||''3VSB''
|#WP||11||12||#HOLD
|}
|}


Line 37: Line 37:
!name!!function
!name!!function
|-
|-
|3VSB||standby 3.3V
|VCC||Voltage (See flash chip datasheet)
|-
|-
|MISO||SPI Master In/Slave Out
|MISO||SPI Master In/Slave Out

Latest revision as of 04:58, 16 October 2020

JSPI1 is a 5x2 or 6x2 2.0mm pitch pin header on many MSI motherboards. It is used to recover from bad boot ROM images. Specifically, it appears to be used to connect an alternate ROM with a working image. Pull the #HOLD line low to deselect the onboard SPI ROM, allowing another SPI ROM to take its place on the bus. Pull the #WP line high to disable write-protection. Some boards use 1.8V flash chips, while others use 3.3V flash chips; Check the flash chip datasheet to determine the correct value.

JSPI1 (5x2)
name pin pin name
VCC 1 2 VCC
MISO 3 4 MOSI
#SS 5 6 SCLK
GND 7 8 GND
#HOLD 9 10 NC
JSPI1 (6x2)
name pin pin name
VCC 1 2 VCC
SO 3 4 SI
#SS 5 6 CLK
GND 7 8 GND
NC 9 10 NC (no pin)
#WP 11 12 #HOLD
name function
VCC Voltage (See flash chip datasheet)
MISO SPI Master In/Slave Out
MOSI SPI Master Out/Slave In
#SS SPI Slave (Chip) Select (active low)
SCLK SPI Clock
GND ground/common
#HOLD SPI hold (active low)
#WP SPI write-protect (active low)
NC Not Connected (or no pin)