Specifications
86 AMD Geode⢠GeodeROM Functional Specification
Serial Port BIOS Support
32087C
8.1.4 Function 03h - Get Port Status
Description:
Reports the status of the serial port. Most of the function reports errors, however, it can be used to check whether data
is available for reading (Data Ready flag, AH = 0).
Passed:
Returns:
Parameter Description
AX 03h
DX Port number:
See "Function 00h - Initialize Port" on page 83
Parameter Description
AH 03h
DX Encoded line status:
Bit 7 = Timeout error occurred
Bit 6 = Transfer shift register empty
Bit 5 = Transfer holding register empty
Bit 4 = Break occurred
Bit 3 = Framing error occurred
Bit 2 = Parity error occurred
Bit 1 = Overrun error occurred
Bit 0 = Data ready
AL Encoded modem status:
Bit 7 = Carrier detect
Bit 6 = Ring indicator
Bit 5 = Data set ready
Bit 4 = Clear to send
Bit 3 = Delta carrier detect
Bit 2 = Trailing edge of ring indicator
Bit 1 = Delta data set ready
Bit 0 = Delta clear to send