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INT 14 - SERIAL I/O - INITIALIZE USART
|
Input |
Output |
|
AX
|
00h |
Parameters |
RS232 Status |
Modem Status |
AX |
|
BX
|
|
|
|
|
BX |
|
CX
|
|
|
|
|
CX |
|
DX
|
Port
Number (0-3) |
|
|
DX |
| ES:DI |
|
|
ES:DI |
| Parameter |
| Bit |
Dec |
Hex |
Description |
| 0 |
1 |
01h |
Word
Size 10 = 7
11 = 8 |
| 1 |
2 |
02h |
| 2 |
4 |
04h |
Stop Bits 0
= 1 stop bit
1 = 2 stop bits |
| 3 |
8 |
08h |
Parity
00 = None
01 = Odd
11 = Even |
| 4 |
16 |
10h |
| 5 |
32 |
20h |
Baud
Rate 000 = 110 baud
001 = 150 baud
010 = 300 baud
011 = 600 baud
100 = 1200 baud
101 = 2400 baud
110 = 4800 baud
111 = 9600 baud |
| 6 |
64 |
40h |
| 7 |
128 |
80h |
| RS232
Status |
| Bit |
Dec |
Hex |
Description |
| 0 |
1 |
01h |
Data ready |
| 1 |
2 |
02h |
Overrun error |
| 2 |
4 |
04h |
Parity error |
| 3 |
8 |
08h |
Framing error |
| 4 |
16 |
10h |
Break detected |
| 5 |
32 |
20h |
Transmission buffer
register empty |
| 6 |
64 |
40h |
Transmission shift
register empty |
| 7 |
128 |
80h |
Time out--if set, other
bits invalid |
| Modem
Status |
| Bit |
Dec |
Hex |
Description |
| 0 |
1 |
01h |
Delta Clear-To-Send |
| 1 |
2 |
02h |
Delta Data-Set-Ready |
| 2 |
4 |
04h |
Trailing edge of ring
detected |
| 3 |
8 |
08h |
Change in receive line
signal detected |
| 4 |
16 |
10h |
Clear-To-Send |
| 5 |
32 |
20h |
Data-Set-Ready |
| 6 |
64 |
40h |
Ring detected |
| 7 |
128 |
80h |
Receive line signal
detected |
|