SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Figure 12-492 shows a device with integrated EMAC and MDIO interfaced via a RGMII connection in a typical system. The individual MCU_CPSW0 and MDIO signals for the RGMII interface are summarized in Table 12-927.
Signal | Device Pin(s) | I/O(1) | Description |
---|---|---|---|
RGMII1_TD[3:0] | MCU_RGMII1_TD[3:0] | O | The transmit data pins are a collection of 4 bits of data. TD0 is the least-significant bit (LSB). The signals are valid only when RGMII1_TCTL is asserted. |
RGMII1_TCTL | MCU_RGMII1_TX_CTL | O | Transmit Control/enable. The transmit enable signal indicates that the TD pins are generating data for use by the PHY. |
RGMII1_TCLK | MCU_RGMII1_TXC | O | The transmit reference clock. The clock is 2.5 MHz at 10 Mbps operation, 25 MHz at 100 Mbps operation, and 125 MHz at 1000 Mbps of operation. |
RGMII1_RD[3:0] | MCU_RGMII1_RD[3:0] | I | The receive data pins are a collection of 4 bits of data. RD0 is the least-significant bit (LSB). |
The signals are valid only when RGMII1_RCTL is asserted | |||
RGMII1_RCTL | MCU_RGMII1_RX_CTL | I | The receive data valid/control signal indicates that the RD pins are nibble data for use by the EMAC. |
RGMII1_RCLK | MCU_RGMII1_RXC | I | The receive clock is a continuous clock that provides the timing reference for receive operations. The clock is generated by the PHY and is 2.5 MHz at 10 Mbps operation, 25 MHz at 100 Mbps operation, 125 MHz at 1000 Mbps of operation. |
MDIO_MCLK | MCU_MDIO0_MDC | O | Management data clock (MDIO_MCLK). The MDIO data clock is sourced by the MDIO module on the system. It is used to synchronize MDIO data access operations done on the MCU_MDIO0_MDIO pin. |
MDIO_MDIO | MCU_MDIO0_MDIO | I/O | The MCU_MDIO0_MDIO pin drives PHY management data into and out of the PHY by way of an access frame consisting of start of frame, read/write indication, PHY address, register address, and data bit cycles. The MCU_MDIO0_MDIO pin acts as an output for all but the data bit cycles at which time it is an input for read operations. |
The Control Module registers assign the specific function to the device pads. For more information on Control Module settings, see Pad Configuration Registers in Control Module (CTRL_MMR) and the device-specific Datasheet.