请大虾帮忙看下下面的小程序，用bit对象进行数据传输。当clk在250HZ以上时，数据传输就不正确了，不知道是什么原因。希望大虾帮忙解答。不知道利用IO8,IO9,IO10这三个管脚进行数据传输，有什么更好更快捷的方法。谢谢了 IO_8 output bit tx; IO_9 input bit clk; IO_10 input bit rx; char rxState,txState; char rxData; char rxBuffer,txBuffer; char rflag; msg_tag OUT1; mtimer repeating mt = 500; domain_struct card_domain1; when(reset) { update_clone_domain(&card_domain1,0); io_change_init(clk); rxState = 0; txState = 0; rxBuffer = 0; txBuffer = 0x55; rflag = 0; } when(io_changes(clk)) { char temp; if(input_value == 1) {//posedge:detect rx switch(rxState) { case 0: { if(io_in(rx) == 0) {//the start bit rxData = 0; rxState = 1; } break; } case 1: { temp = io_in(rx); temp = temp & 0x01; rxData = temp; rxState = 2; break; } case 2: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 1; rxState = 3; break; } case 3: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 2; rxState = 4; break; } case 4: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 3; rxState = 5; break; } case 5: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 4; rxState = 6; break; } case 6: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 5; rxState = 7; break; } case 7: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 6; rxState = 8; break; } case 8: { temp = io_in(rx); temp = temp & 0x01; rxData = rxData | temp << 7; rxState = 9; break; } case 9: { temp = io_in(rx); temp = temp & 0x01; if(temp == 0x01) {//end bit rxBuffer = rxData; msg_out.tag = OUT1; msg_out.code = 0; msg_out.data[0] = rxBuffer; msg_out.service = UNACKD; msg_out.dest_addr.bcast.type=3; msg_out.dest_addr.bcast.domain=0; msg_out.dest_addr.bcast.backlog=1; msg_out.dest_addr.bcast.rpt_timer=0; msg_out.dest_addr.bcast.retry=0; msg_out.dest_addr.bcast.tx_timer=0; msg_out.dest_addr.bcast.subnet=0; msg_send(); // txBuffer = rxBuffer + 0x10; // rflag = 1; } rxState = 0; break; } } } else if(rflag == 1) {//negedge:send data switch(txState) { case 0: { io_out(tx,1); txState = 10; break; } case 10: { io_out(tx,0); txState = 1; break; } case 1: { txState = 2; if((txBuffer & 0x01) == 0x01) io_out(tx,1); else io_out(tx,0); break; } case 2: { txState = 3; if((txBuffer & 0x02) == 0x02) io_out(tx,1); else io_out(tx,0); break; } case 3: { txState = 4; if((txBuffer & 0x04) == 0x04) io_out(tx,1); else io_out(tx,0); break; } case 4: { txState = 5; if((txBuffer & 0x08) == 0x08) io_out(tx,1); else io_out(tx,0); break; } case 5: { txState = 6; if((txBuffer & 0x10) == 0x10) io_out(tx,1); else io_out(tx,0); break; } case 6: { txState = 7; if((txBuffer & 0x20) == 0x20) io_out(tx,1); else io_out(tx,0); break; } case 7: { txState = 8; if((txBuffer & 0x40) == 0x40) io_out(tx,1); else io_out(tx,0); break; } case 8: { txState = 9; if((txBuffer & 0x80) == 0x80) io_out(tx,1); else io_out(tx,0); break; } case 9: { txState = 0; io_out(tx,1); rflag = 0; break; } default: { txState = 0; io_out(tx,1); rflag = 0; b