[Figure 1, callout 17]
I2C bus I2C0 connects Zynq UltraScale+ RFSoC U1 PS Bank 500 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 accepts
various alarm inputs. 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 Name | Ref. Designator | Device | |
| SDA | I2C0_SDA |
Refer to connections shown in the figure above. TCA6416A U15 Addr. 0x20 |
||
| SCL | I2C0_SCL | |||
| P00 | MAX6643_OT_B | OT_B | U50 | MAX6643 |
| P01 | MAX6643_FANFAIL_B | FANFAIL_B | U50 | MAX6643 |
| P02 | MIO26_PMU_INPUT_LS | PS_MIO26 | U1 | XCZU67DR |
| P03 | DAC_AVTT_VOUT_SEL | G | Q36 | NDS331N |
| P04 | SI5381_INT_ALM | INTRB | U43 | SI5381A |
| P05 | IIC_MUX_RESET_B | RESET_B | U20 | TCA9548A |
| P06 | GEN3_EXP_RESET_B | B | U34 | SN74LVC1G08 |
| P07 | MAX6643_FULL_SPEED | FULLSPD | U50 | MAX6643 |
| P10 | FMCP_HSPC_PRSNT_M2C_B | PRSNT_M2C_L | J28(H) | ASP_184329_01 |
| PRSNT_M2C_L | J28(N) | ASP_184329_01 | ||
| P13 | VCCINT_VRHOT_B | VRHOT_ICRIT# | U104 | IR35215 |
| P15 | 8A34001_EXP_RST_B | A | U415 | SN74LVC1G08 |
| P16 | IRPS5401_ALERT_B | SM_ALERT# | U104 | IR35215 |
| ALERT_B | U53, U55 | IRPS5401 | ||
| SALERT# | U112, U123, U127 | IR38164 | ||
| P17 | INA226_PMBUS_ALERT | 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 |