PMC MIO[46:47] I2C0 Bus

[Figure 1, callout 11]

Bus I2C0 connects the XCVM1802 U1 PS bank 501 and the XCZU4EG system controller U125 PS bank 501 to a GPIO 16-bit port expander (TCA6416A U233) and I2C switch (TCA9548A U33). The port expander enables accepting various fan controller, FMCP connector, and power system status inputs. Bus I2C0 also provides access to power system PMBus power controllers and INA226 power monitors, as well as three SI570 components via the U33 TCA9548A switch. TCA6416A U233 is pin-strapped to respond to I2C address 0x20. The TCA9548A U33 switch is set to 0x74.

The following figure shows the I2C0 bus connectivity.

Figure 1. I2C0 Bus Topology

The devices on each port of the I2C0 U233 PCA9548A port expander and on each bus of the I2C0 U33 TCA9548A switch are listed in the following two tables. The I2C0 target device I2C addresses are listed in the third table below.

Table 1. I2C0 Port Expander TCA6416A U233 Address 0x20 Connections
TCA6416A U233		Schematic Net Name	Connected To
Pin Name	Pin No.	Schematic Net Name	Pin No.	Pin Name	Reference Designator	Device
SDA	23	I2C0_SDA	See the "I2C0 Bus Topology" figure. TCA6416A U233 Addr. `0x20`
SCL	22	I2C0_SCL
P00	4	MAX6643_OT_B (1)	9	OT_B	U64	MAX6643
P01	5	MAX6643_FANFAIL_B (1)	4	FANFAIL_B	U64	MAX6643
P04	8	PMBUS2_INA226_ALERT (1)	3	ALERT	14x INA226	INA226
P07	11	MAX6643_FULLSPD (1)	6	FULLSPD	U64	MAX6643

P10	13	FMCP1_FMC_PRSNT_M2C_B	H2	PRSNT_M2C_L	J51(H)	ASP_184329_01
P11	12	FMCP2_FMC_PRSNT_M2C_B	H2	PRSNT_M2C_L	J53(H)	ASP_184329_01
P12	15	FMCP1_FMCP_PRSNT_M2C_B	Z1	HSPC_PRSNT_M2C_L	J51(N)	ASP_184329_01
P13	16	FMCP2_FMCP_PRSNT_M2C_B	Z1	HSPC_PRSNT_M2C_L	J53(N)	ASP_184329_01
P14	17	VCCINT_VRHOT_B	14	VRHOT_ICRIT#	U152	IR35215
P15	18	8A34001_EXP_RST_B	1	A	U221	SN74LVC1G08
P16	19	IRPS5401_ALERT_B	-	Not connected	In schematic	Delete
P17	20	PMBUS1_INA226_ALERT (1)	3	ALERT	5x INA226	INA226

Table 2. I2C0 Multiplexer TCA9548A U33 Address 0x74 Connections
TCA9548A U33		Schematic Net Name	Connected To
Pin Name	Pin No.	Schematic Net Name	Pin No.	Pin Name	Reference Designator	Device
SDA	19	I2C0_SDA	See the "I2C0 Bus Topology" figure; TCA9548A U33 Addr. `0x74`
SCL	18	I2C0_SCL
SD0/SC0	4/5	PMBUS_SDA/SCL	9,10	NA	J98	PMBUS HDR
SD0/SC0	4/5	PMBUS_SDA/SCL	Miscellaneous power components; see Board Power System for details
SD1/SC1	6/7	PMBUS1_INA226_SDA/SCL	4,5	SDA, SCL	5x INA226	INA226
SD2/SC2	8/9	PMBUS2_SDA/SCL	9,10	NA	J104	PMBUS HDR
SD2/SC2	8/9	PMBUS2_SDA/SCL	Miscellaneous power components; see Board Power System for details
SD3/SC3	10/11	PMBUS2_INA226_SDA/SCL	4,5	SDA, SCL	14x INA226	INA226
SD4/SC4	13/14	LP_I2C_SM_SDA/SCL	NA	Not connected	NA	NA
SD5/SC5	15/16	zSFP_SI570_SDA/SCL	7,8	SDA, SCL	U192	SI570
SD6/SC6	17/18	USER_SI570_1_CLOCK_SDA/SCL	7,8	SDA, SCL	U205	SI570
SD7/SC7	19/20	USER_SI570_2_CLOCK_SDA/SCL	NA	Not connected	NA	NA

Table 3. I2C0 Port Expander TCA6416A U233 Address 0x20 Connections
I2C Devices	I2C Switch Position	I2C Address		Device
I2C0 Bus
TCA6416A 16-bit port expander	N/A	`0b1110101`	`0x20`	U233 TCA6416A
Function	Port	Direction
MAX6643_OT_B	P00	IN	N/A	U64 MAX6643
MAX6643_FANFAIL_B	P01	IN	N/A	U64 MAX6643
N/A	P02-P03 NC	N/A	N/A	N/A
PMBUS2_INA226_ALERT	P04	IN	N/A	U166, U168, U172, U173, U174, U176, U177, U178, U180, U182, U184, U186, U188, U234 INA226, U125 ZU4EG
N/A	P05-P06 NC	N/A	N/A	N/A
MAX6643_FULLSPD	P07	OUT	N/A	U64 MAX6643

FMCP1_FMC_PRSNT_M2C_B	P10	IN	N/A	J51 FMCP HSPC
FMCP2_FMC_PRSNT_M2C_B	P11	IN	N/A	J53 FMCP HSPC
FMCP1_FMCP_PRSNT_M2C_B	P12	IN	N/A	J51 FMCP HSPC
FMCP2_FMCP_PRSNT_M2C_B	P13	IN	N/A	J53 FMCP HSPC
VCCINT_VRHOT_B	P14	IN	N/A	U152 IR35215
8A34001_EXP_RST_B	P15	IN	N/A	U221 SN74LVC1G08
PMBUS_ALERT	P16	IN	N/A	U152, U160, U167, U175, U179, U181, U183, U185, U187, U189, U194, U195 Various Vreg, U125 ZU4EG
PMBUS1_INA226_ALERT	P17	IN	N/A	U65,U161-U165 INA226, U125 ZU4EG

TCA9548A 8-Chan. bus switch	N/A	`0b1110101`	`0x75`	U33 TCA9548A
Function	Port	Binary Format	Hex Format
PMBUS_SDA/SCL	0	`0b00010011`-`0b00010100`, `0b00010110`-`0b00010111`, `0b00011001`-`0b00100000`	`0x13`, `0x14`, `0x16`, `0x17`, `0x19`-`0x20`	See tables in Board Power System
PMBUS1_INA226_SDA/SCL	1	`0b01000000`-`0b01000101`	`0x40`-`0x45`	U65,U161-U165 INA226; see tables in Board Power System
PMBUS2_INA226_SDA/SCL	3	`0b01000000`-`0b01000101`	`0x40`-`0x4D`	U166, U168, U172, U173, U174, U176, U177, U178, U180, U182, U184, U186, U188, U234 INA226; see tables in Board Power System
No connect	4	NA	NA	NA
zSFP_SI570_SDA/SCL	5	`0b1011101`	`0x5D`	U192 SI570
USER_SI570_1_CLOCK_SDA/SCL	6	`0b1011111`	`0x5F`	U205 SI570
No Connect	7	NA	NA	NA