描述:
各位一定知道对于串口、并口来说,WINDOWS(我不太清楚,可能是BIOS定的吧)都有对应的寄存器的某些Bit可以与这些口上的各个引脚有一一对应关系,通过设置或读取这些Bit就可以改变或得到这些引脚上的电平状态。不知道计算机上所有常见接口还有哪些可以像串并口这样控制,能否给点详细资料?
解决方案1:
去看 SYSTEM MEMORY SPACE 的 400H 的地方
40:00 COM1 PORT ADDRESS
40:02 COM2 PORT ADDRESS
40:04 COM3 PORT ADDRESS
40:06 COM4 PORT ADDRESS
40:08 LPT1 PORT ADDRESS
40:0A LPT2 PORT ADDRESS
40:0C LPT3 PORT ADDRESS
40:0E LPT4 PORT ADDRESS
COMn PORT ADDRESS + OFFSETx
x = 0: Transmit/Receive Buffer, Baud Rate Divisor LSB if Bit 7 of LCR is set
x = 1: Interrupt Enable Register, Baud Rate Divisor MSB if Bit 7 of LCR is set
x = 2: Interrupt Identification Register
x = 3: Line Control Register
x = 4: Modem Control Register
x = 5: Line Status Register
x = 6: Modem Status Register
x = 7: Scratch Pad Register
你要问硬件生产厂去了。
解决方案3: Dos里很多,Windows不清楚。
顶一个先!