CAN总线控制器IP核代码分析

module */

.rx_idle(rx_idle),

.transmitting(transmitting),

.last_bit_of_inter(last_bit_of_inter)

);

can_bsp i_can_bsp

(

.clk(clk_i),

.rst(rst),

/* From btl module */

.sample_point(sample_point),

.sampled_bit(sampled_bit),

.sampled_bit_q(sampled_bit_q),

.tx_point(tx_point),

.hard_sync(hard_sync),

.addr(addr),

.data_in(data_in),

.data_out(data_out_fifo),

.fifo_selected(data_out_fifo_selected),/* Mode register */

.reset_mode(reset_mode),

.listen_only_mode(listen_only_mode),

.acceptance_filter_mode(acceptance_filter_mode),

.self_test_mode(self_test_mode),

/* Command register */

.release_buffer(release_buffer),

.tx_request(tx_request),

.abort_tx(abort_tx),

.self_rx_request(self_rx_request),

.single_shot_transmission(single_shot_transmission),

/* Arbitration Lost Capture Register */

.read_arbitration_lost_capture_reg(read_arbitration_lost_capture_reg),

/* Error Code Capture Register */

.read_error_code_capture_reg(read_error_code_capture_reg),

.error_capture_code(error_capture_code),

/* Error Warning Limit register */

.error_warning_limit(error_warning_limit),

/* Rx Error Counter register */

.we_rx_err_cnt(we_rx_err_cnt),

/* Tx Error Counter register */

.we_tx_err_cnt(we_tx_err_cnt),

/* Clock Divider register */

.extended_mode(extended_mode),

/* output from can_bsp module */

.rx_idle(rx_idle),

.transmitting(transmitting),

.last_bit_of_inter(last_bit_of_inter),

.set_reset_mode(set_reset_mode),

.node_bus_off(node_bus_off),

.error_status(error_status),

.rx_err_cnt({rx_err_cnt_dummy, rx_err_cnt[7:0]}), // The MSB is not displayed. It is just used for easier calculation (no counter overflow).

.tx_err_cnt({tx_err_cnt_dummy, tx_err_cnt[7:0]}), // The MSB is not displayed. It is just used for easier calculation (no counter overflow).

.transmit_status(transmit_status),

.receive_status(receive_status),

.tx_successful(tx_successful),

.need_to_tx(need_to_tx),

.overrun(overrun),

.info_empty(info_empty),

.set_bus_error_irq(set_bus_error_irq),

.set_arbitration_lost_irq(set_arbitration_lost_irq),

.arbitration_lost_capture(arbitration_lost_capture),

.node_error_passive(node_error_passive),

.node_error_active(node_error_active),

.rx_message_counter(rx_message_counter),

/* This section is for BASIC and EXTENDED mode */

/* Acceptance code register */

.acceptance_code_0(acceptance_code_0),

/* Acceptance mask register */

.acceptance_mask_0(acceptance_mask_0),

/* End: This section is for BASIC and EXTENDED mode */

/* This section is for EXTENDED mode */

/* Acceptance code register */

.acceptance_code_1(acceptance_code_1),

.acceptance_code_2(acceptance_code_2),

.acceptance_code_3(acceptance_code_3),

/* Acceptance mask register */

.acceptance_mask_1(acceptance_mask_1),

.acceptance_mask_2(acceptance_mask_2),

.acceptance_mask_3(acceptance_mask_3),

/* End: This section is for EXTENDED mode */

/* Tx data registers. Holding identifier (basic mode), tx frame information (extended mode) and data */

.tx_data_0(tx_data_0),

.tx_data_1(tx_data_1),

.tx_data_2(tx_data_2),

.tx_data_3(tx_data_3),

.tx_data_4(tx_data_4),

.tx_data_5(tx_data_5),

.tx_data_6(tx_data_6),

.tx_data_7(tx_data_7),

.tx_data_8(tx_data_8),

.tx_data_9(tx_data_9),

.tx_data_10(tx_data_10),

.tx_data_11(tx_data_11),

.tx_data_12(tx_data_12),

/* End: Tx data registers */

/* Tx signal */

.tx(tx_out),

.tx_oen(tx_oen)

);

assign tx_o = tx_oen? 1'bz : tx_out;

// Multiplexing wb_dat_o from registers and rx fifo

always @ (extended_mode or addr or reset_mode)

begin

if (extended_mode (~reset_mode) ((addr >= 8'd16) (addr = 8'd28)) | (~extended_mode) ((addr >= 8'd20) (addr = 8'd29)))

data_out_fifo_selected = 1'b1;

else

dat