INTERCONNECT (Internal digital routing)

group group_hal_interconnect

High level interface to the Cypress digital routing.


Facilities for runtime manipulation of the on chip routing. The following types of connections are supported:

  • Connection from a peripheral to a pin. (A dedicated connection must exist between the pin and the peripheral; see the device datasheet for more details)

  • Connecting two peripherals in hardware using the on-chip trigger signaling

Quick Start

  • cyhal_connect_pin can be used to connect a pin to a peripheral.(A dedicated connection must exist between the pin and the peripheral; see the device datasheet for more details)

  • cyhal_disconnect_pin can be used to disconnect a pin from a peripheral. The drive mode will be reset to High-Z after disconnecting

Code Snippets

Snippet 1: Connecting a pin to TCPWM block

The following code snippet demonstrates connecting a GPIO pin to an active TCPWM block on a device using the cyhal_connect_pin. It is assumed that the TCPWM is already configured and active.

    // Find out the resource block that connects the specified pins from the provided resource pin
    // mapping table cyhal_pin_map_tcpwm_line. This example connects the pin to the TCPWM line pin
    const cyhal_resource_pin_mapping_t* map =
        _CYHAL_UTILS_GET_RESOURCE(P2_4, cyhal_pin_map_tcpwm_line);

    // Obtain the GPIO pin resource
    cyhal_resource_inst_t pin_rsc = _cyhal_utils_get_gpio_resource(P2_4);

    // Reserve the resource in hardware manager to prevent other HAL blocks from using it
    cy_rslt_t status = cyhal_hwmgr_reserve(&pin_rsc);
    if (CY_RSLT_SUCCESS == status)
        // The resource is free, connect it to the block
        status = cyhal_connect_pin(map);
        if (CY_RSLT_SUCCESS != status)

Snippet 2: Connecting a Timer output signal to a DMA input signal

The following code snippet demonstrates configuring and connecting a Timer which will overflow every 2 seconds and, in doing so, trigger a DMA channel start.

    cyhal_source_t timer_source;
    cyhal_dma_t    dma;
    cyhal_timer_t  timer;

    uint32_t src_arr[] = { 100, 200 };
    uint32_t dst_arr[] = { 0, 0 };

    const cyhal_timer_cfg_t timer_cfg =
        .compare_value = 0,
        .period        = 20000,
        .direction     = CYHAL_TIMER_DIR_UP,
        .is_compare    = false,
        .is_continuous = true,
        .value         = 0

    const cyhal_dma_cfg_t dma_cfg =
        .src_addr       = (uint32_t)src_arr,
        .src_increment  = 1,
        .dst_addr       = (uint32_t)dst_arr,
        .dst_increment  = 1,
        .transfer_width = 32,
        .length         = 2,
        .burst_size     = 0,
        .action         = CYHAL_DMA_TRANSFER_FULL,

    // Configure simple dma transfer from src_arr to dst_arr
    cyhal_dma_configure(&dma, &dma_cfg);

    // Setup timer to run continously, overflowing every 2 seconds
    cyhal_timer_init(&timer, NC, NULL);
    cyhal_timer_configure(&timer, &timer_cfg);
    cyhal_timer_set_frequency(&timer, 10000);

    // Connect timer overflow trigger to DMA start
    cyhal_timer_enable_output(&timer, CYHAL_TIMER_OUTPUT_OVERFLOW, &timer_source);
    cyhal_dma_connect_digital(&dma, timer_source, CYHAL_DMA_INPUT_TRIGGER_ALL_ELEMENTS);

    // Once timer is started, a DMA transfer will be triggered every 2 seconds (when the timer
    // overflows) until the connection is disabled.

    // Disable the connection
    cyhal_timer_disable_output(&timer, CYHAL_TIMER_OUTPUT_OVERFLOW);
    cyhal_dma_disconnect_digital(&dma, timer_source, CYHAL_DMA_INPUT_TRIGGER_ALL_ELEMENTS);



cy_rslt_t cyhal_connect_pin(const cyhal_resource_pin_mapping_t *pin_connection)

Connect a pin to a peripheral terminal.

This will route a direct connection from the pin to the peripheral. Any previous direct connection from the pin will be overriden.


Snippet 1: Connecting a pin to TCPWM block

The status of the connect request

  • [in] pin_connection: The pin and target peripheral terminal to be connected

cy_rslt_t cyhal_disconnect_pin(cyhal_gpio_t pin)

Disconnect a peripheral from a pin.

This will also reset the pin’s drive mode to High-Z.


The status of the disconnect request

  • [in] pin: The pin to be disconnected