Interfaces
UART
UC6580 makes use of two UART interfaces: UART1 and UART2. Both of them can be used for communication with a host.
By default, PIO6/PIO7 corresponds to UART1, which serves as the main UART in standard firmware version. The communication interface of UC6580 can be mapped to different PIO interfaces via BOOT_MODE. PIO6/PIO7 can also be used as SPI, and in this case, there is no UART1 function. See the description in section Boot Mode for the use of BOOT_MODE and the corresponding communication interface mapping.
UART2 can use PIO15/PIO16. It is mainly used for transmitting or debugging auxiliary information.
SPI slave
UC6580 uses SPI slave interface as an optional way to communicate with the host to transfer data. At the same time, it supports loading firmware via the SPI slave interface. The maximum transmission rate using SPI slave is 8 Mbps, and the maximum SPI clock frequency is 8 MHz. When the SPI slave loads the firmware, the maximum transmission rate is 4 Mbps.
The SPI slave interface shares PIO6/PIO7 and PIO8/PIO9 with UART1 and I2C respectively. Users can select the communication interface via D_SEL and BOOT_MODE. If PIO6/PIO7/PIO8/PIO9 is used as SPI slave interface, there are no UART1 and I2C1 functions; if PIO6/PIO7 and PIO8/PIO9 are used as UART1 and I2C1, there is no SPI slave interface.
When the SPI slave interface is used for host communication, PIO14 should be used as the SRDY (Slave Ready) signal to indicate whether the SPI slave is ready.
SPI master
UC6580 provides SPI master interface by configuring PIO0/PIO1/PIO3/PIO4, which can be used to communicate with or control other SPI slave devices. The maximum transmission rate of the SPI master interface is 16 Mbps, and the maximum SPI clock frequency is 16 MHz.
The SPI master interface is disabled by default.
I2C
UC6580 provides two I2C interfaces (I2C1 and I2C2) to communicate with the host or sensor, of which the I2C1 interface works in slave mode for firmware loading and communicating with the host, and I2C2 works in master mode to connect to the external sensor. The I2C interfaces are compatible with the I2C protocol, supporting the transmission rates of 100 Kbps, 400 Kbps, and 3.4 Mbps.
By default, the I2C1 interface uses PIO8/PIO9, and the BOOT_MODE pin should be in pull-up or open-circuit state when booting. For more information, please refer to the description in section 5.2. I2C2 can be mapped to PIO13/PIO14 through customized firmware.
Serial Flash Interface
Serial Flash interface is used to connect UC6580 with external SPI Flash. SPI Flash can be used for firmware storage and update.
The serial Flash interface uses PIO0/PIO1/PIO2/PIO3/PIO4/PIO5 only when the BOOT_MODE pin is in pull-up or open-circuit state when booting; otherwise, the serial Flash interface is invalid.