【文章內(nèi)容簡(jiǎn)介】 rising_edge = 139。b0。falling_edge = 139。b0。case (m1_state)m1_clk_h : //時(shí)鐘高電平beginsync_clk = 139。b1。if(~ps2_clk_in_r)m1_next_state = m1_falling_edge。elsem1_next_state = m1_clk_h。endm1_falling_edge : //時(shí)鐘下降沿beginfalling_edge = 139。b1。m1_next_state = m1_falling_wait。endm1_falling_wait : //等待5US延時(shí)防止毛刺干擾beginif(timer_5us_done)m1_next_state = m1_clk_l。elsem1_next_state = m1_falling_wait。endm1_clk_l : //時(shí)鐘低電平beginif(ps2_clk_in_r)m1_next_state = m1_rising_edge。elsem1_next_state = m1_clk_l。endm1_rising_edge : //時(shí)鐘上升沿beginrising_edge = 139。b1。m1_next_state = m1_rising_wait。endm1_rising_wait : //等待5US延時(shí)防止毛刺干擾beginsync_clk = 139。b1。if(timer_5us_done)m1_next_state = m1_clk_h。elsem1_next_state = m1_rising_wait。enddefault : m1_next_state = m1_clk_h。endcaseendalways @(posedge clock)beginif(reset == 139。b1)m2_state = m2_reset。elsem2_state = m2_next_state。endalways @(m2_stateor qor falling_edgeor rising_edgeor watchdog_timer_doneor bit_countor packet_goodor ps2_data_in_ror sync_clk)beginps2_clk_out_r = 139。b1。ps2_data_out_r = 139。b1。ps2_clk_dir_r = 139。b0。ps2_data_dir_r = 139。b0。data_ready_r = 139。b0。case (m2_state)m2_reset : beginm2_next_state = m2_hold_clk_l。endm2_wait :beginif (falling_edge)m2_next_state = m2_gather。elsem2_next_state = m2_wait。endm2_gather : //判斷數(shù)據(jù)是否收完beginif (watchdog_timer_done amp。amp。 (bit_count == `TOTAL_BITS))m2_next_state = m2_verify。else if (watchdog_timer_done amp。amp。 (bit_count `TOTAL_BITS))m2_next_state = m2_hold_clk_l。elsem2_next_state = m2_gather。endm2_verify : //檢驗(yàn)數(shù)據(jù)包是否正確beginif (packet_good)m2_next_state = m2_use。elsem2_next_state = m2_wait。endm2_use : //數(shù)據(jù)包是否正確begindata_ready_r = 139。b1。m2_next_state = m2_wait。endm2_hold_clk_l : //拉低時(shí)鐘線400US，準(zhǔn)備發(fā)送命令beginps2_clk_dir_r = 139。b1。ps2_clk_out_r = 139。b0。if(watchdog_timer_done amp。amp。 ~sync_clk)m2_next_state = m2_data_low_1。elsem2_next_state = m2_hold_clk_l。endm2_data_low_1 : //發(fā)送起始位0,d[0],d[1]beginps2_data_dir_r = 139。b1。ps2_data_out_r = 139。b0。if (falling_edge amp。amp。 (bit_count == 639。d2))m2_next_state = m2_data_high_1。elsem2_next_state = m2_data_low_1。endm2_data_high_1 : //發(fā)送位d[2]beginps2_data_dir_r = 139。b1。if (falling_edge)m2_next_state = m2_data_low_2。elsem2_next_state = m2_data_high_1。endm2_data_low_2 :beginps2_data_dir_r = 139。b1。ps2_data_out_r = 139。b0。 //發(fā)送位d[3]if (falling_edge)m2_next_state = m2_data_high_2。elsem2_next_state = m2_data_low_2。endm2_data_high_2 : //發(fā)送位d[4],d[5],d[6],d[7]beginps2_data_dir_r = 139。b1。if (falling_edge amp。amp。 (bit_count == 639。d8))m2_next_state = m2_data_low_3。elsem2_next_state = m2_data_high_2。endm2_data_low_3 : //發(fā)送奇偶校驗(yàn)位beginps2_data_dir_r = 139。b1。ps2_data_out_r = 139。b0。if(falling_edge)m2_next_state = m2_data_high_3。elsem2_next_state = m2_data_low_3。endm2_data_high_3 : //停止位1,應(yīng)答處理beginif (falling_edge amp。amp。 ps2_data_in_r)m2_next_state = m2_hold_clk_l。 //有錯(cuò)誤產(chǎn)生,重新復(fù)位else if (falling_edge amp。amp。 ~ps2_data_in_r)m2_next_state = m2_await_response。elsem2_next_state = m2_data_high_3。endm2_await_response :beginif (bit_count == 639。d22)m2_next_state = m2_verify。elsem2_next_state = m2_await_response。enddefault : m2_next_state = m2_wait。endcaseendalways @(posedge clock)beginif(reset == 139。b1)bit_count = 639。d0。 //復(fù)位時(shí)計(jì)數(shù)器清零else if(falling_edge)bit_count = bit_count + 639。d1。else if(watchdog_timer_done)bit_count = 639。d0。 //接收完一個(gè)數(shù)據(jù)包后計(jì)數(shù)器清零end//移位寄存器，在時(shí)鐘的下降沿鎖存數(shù)據(jù)//功能：接收PS2發(fā)送到來(lái)的數(shù)據(jù)always @(posedge clock)beginif (reset == 139。b1) q = `TOTAL_BITS39。d0。 else if (falling_edge) q = {ps2_data_in_r,q[`TOTAL_BITS1:1]}。endalways @(posedge clock)begin if(reset || rising_edge || falling_edge) watchdog_timer_count = 0。 else if(~watchdog_timer_done) watchdog_timer_count = watchdog_timer_count + 1。endassign watchdog_timer_done = (watchdog_timer_count==WATCHDOG_TIMER_VALUE1)。//緩沖時(shí)間5US計(jì)數(shù)器always @(posedge clock)begin if (reset || falling_edge || rising_edge ) timer_5us_count = 0。 else timer_5us_count = timer_5us_count + 1。endassign timer_5us_done = (timer_5us_count == TIMER_5US_VALUE1)。//驗(yàn)證收到的數(shù)據(jù)包數(shù)據(jù)是否有效、正確assign packet_good = ( (q[0] == 139。b0) //第一字節(jié)起始位 amp。amp。 (q[10] == 139。b1) //第一字節(jié)停止位 amp。amp。 (q[11] == 139。b0) //第二字節(jié)起始位 amp。amp。 (q[21] == 139。b1) //第二字節(jié)停止位 amp。amp。 (q[22] == 139。b0) //第三字節(jié)起始位 amp。amp。 (q[32] == 139。b1) //第三字節(jié)停止位 amp。amp。 (q[9] == ~^q[8:1]) //第一字節(jié)奇驗(yàn)證位 amp。amp。 (q[20] == ~^q[19:12]) //第二字節(jié)奇驗(yàn)證位 amp。am