User`s manual

DIGITAL-LOGIC AG MSMP5 / P3 SEN/SEV Manual V1.6A
66
I/O Ad-
dress
Read/Write
Status
Description
03FDh R Line status register - serial port 1
bit 7 = Reserved
bit 6 = 1 Transmitting shift and holding registers
empty
bit 5 = 1 Transmitter shift register empty
bit 4 = 1 Break interrupt
bit 3 = 1 Framing error
bit 2 = 1 Overrun error
bit 0 = 1 Data ready
03FEh R Modem status register - serial port 1
bit 7 = 1 Data Carrier Detect
bit 6 = 1 Ring Indicator
bit 5 = 1 Data Set Ready
bit 4 = 1 Clear To Send
bit 3 = 1 Delta Data Carrier
bit 2 = 1 Trailing Edge Ring Indicator
bit 1 = 1 Delta Data Set Ready
bit 0 = 1 Delta Clear To Send
03FFh R / W Scratch register - serial port 1 (used for diagnostics)
0A79h W PnP Data write register (only for PnP devices)