[Figure 1, callout 17]
I2C bus I2C0 connects Zynq UltraScale+ RFSoC U1 PS Bank 500, PL bank 89, and the system controller U38 to a GPIO 16-bit port
expander (TCA6416A U15) and I2C switch (PCA9544A U17). The port expander enables
controlling resets and power system enable pins, and accepting various alarm inputs
without requiring the PL-side to be configured. The I2C0 bus also provides access to
the PMBUS power controllers and INA226 power monitors through the U17 PCA9544A
switch. TCA6416A U15 is pin-strapped to respond to I2C address
0x20. The PCA9544A U17 switch is set to 0x75.
The following figure shows a high-level view of the I2C0 bus connectivity.
The following table identifies the devices on each port of the I2C0 U15 TCA6416A port expander.
| TCA6416A U15 | Schematic Net Name | Connected To | ||||
|---|---|---|---|---|---|---|
| Pin Name | Pin No. | Pin No. | Pin Name | Reference Designator | Device | |
| SDA | 23 | I2C0_SDA |
Refer to connections shown in the figure above. TCA6416A U15 Addr. 0x20 |
|||
| SCL | 22 | I2C0_SCL | ||||
| P00 | 4 | MAX6643_OT_B | 9 | OT_B | U50 | MAX6643 |
| P01 | 5 | MAX6643_FANFAIL_B | 4 | FANFAIL_B | U50 | MAX6643 |
| P02 | 6 | MIO26_PMU_INPUT_LS | A34 | PS_MIO26 | U1 | XCZU49DR |
| P04 | 8 | DAC_AVTT_VOUT_SEL | 1 | G | Q36 | NDS331N |
| P05 | 9 | IIC_MUX_RESET_B | 3 | RESET_B | U20 | TCA9548A |
| P06 | 10 | GEN3_EXP_RESET_B | 2 | B | U34 | SN74LVC1G08 |
| P07 | 11 | MAX6643_FULL_SPEED | 6 | FULLSPD | U50 | MAX6643 |
| P10 | 13 | FMCP_HSPC_PRSNT_M2C_B | H2 | PRSNT_M2C_L | J28(H) | ASP_184329_01 |
| Z1 | PRSNT_M2C_L | J28(N) | ASP_184329_01 | |||
| P13 | 16 | VCCINT_VRHOT_B | 14 | VRHOT_ICRIT# | U104 | IR35215 |
| P15 | 18 | 8A34001_EXP_RST_B | 1 | A | U415 | SN74LVC1G08 |
| P16 | 19 | IRPS5401_ALERT_B | 11 | SM_ALERT# | U104 | IR35215 |
| 17 | ALERT_B | U53, U55 | IRPS5401 | |||
| 17 | SALERT# | U112, U123, U127 | IR38164 | |||
| P17 | 20 | INA226_PMBUS_ALERT | 3 | ALERT | U57, U58, U59,U60, U61, U62, U63, U64, U65, U67, U71, U75, U77, U124 | INA226 |
The addresses of each target device on the I2C0 U17 PCA9544A switch are identified in the following table.
| PCA9544A U17 (Addr 0x75) Port | I2C0 Bus Device | Target Device Address |
|---|---|---|
| 0 | INA226_PMBus (Power Monitors) | 0X40-0x43, 0x45-0x4E |
| 1 | Not Connected | N/A |
| 2 | IRPS5401_PMBus (Voltage Regulators) | 0X40, 0x43, 0x44, 0x45, 0x4B, 0x4C |
| 3 | SYSMON U1 bank 65 | 0X32 |