Low Power V.32 bis Modem
CMX869
6.6
Tx Data Register
Tx Data Register: 8 or 16-bit write-only.
C-BUS addresses $E3 and $E4
This register may be set to operate in 8 or 16-bit mode by b10 of the General Control Register. This setting
should not be changed once data transmission has started.
1-character mode (General Control Register b10 = 0). C-Bus addresses $E3 and $E4
7
6
5
4
3
2
1
0
Bit:
Byte to be transmitted
2-character mode (General Control Register b10 = 1). C-Bus address $E3 only
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Bit:
First byte to be transmitted
Second byte to be transmitted
This register should only be written to when the Tx Data Ready bit of the Status Register is set to 1.
In Synchronous Tx data mode all 8 bits of a byte are transmitted, bit 0 of each byte being transmitted first.
In Tx Start-Stop modes the specified number of data bits will be taken from the byte in the Tx Data
Register (b0 of the byte first). A Start bit, a Parity bit (if required) and Stop bit(s) will be added
automatically.
© 2004 CML Microsystems Plc
28
D/869/4
CMLMICRO [ CML MICROCIRCUITS ]
