TMP91C824
91C824-146
2008-02-20
(2)
Mode 1 (7-bit UART mode)
7-bit UART mode is selected by setting serial channel mode register
SC0MOD0<SM1:0> to 01.
In this mode, a parity bit can be added. Use of a parity bit is enabled or disabled by
the setting of the serial channel control register SC0CR<PE> bit; whether even parity
or odd parity will be used is determined by the SC0CR<EVEN> setting when
SC0CR<PE> is set to 1 (Enabled).
Example: When transmitting data of the following format, the control registers
should be set as described below. This explanation applies to channel 0.
*
Clock state
System clock:
High frequency (fc)
Clock gear:
1 (fc)
Prescaler clock: System clock
7 6 5 4 3 2 1 0
PCCR
←
X X
−
−
−
− −
1
PCFC
←
X X
−
X
−
−
X 1
Set PC0 to function as the TXD0 pin.
SC0MOD0
←
−
−
−
−
0 1 0 1
Select 7-bit UART mode.
SC0CR
←
−
1 1
−
−
− − −
Add even parity.
BR0CR
←
0 0 1 0 0 1 0 1
Set the transfer rate to 2400 bps.
INTES0
←
−
1 0 0
−
− − −
Enable the INTTX0 interrupt and set it to interrupt level 4.
SC0BUF
←
* * * * * * * *
Set data for transmission.
X: Don’t care,
−
: No change
(3)
Mode 2 (8-bit UART mode)
8-bit UART mode is selected by setting SC0MOD0<SM1:0> to 10. In this mode, a
parity bit can be added (use of a parity bit is enabled or disabled by the setting of
SC0CR<PE>); whether even parity or odd parity will be used is determined by the
SC0CR<EVEN> setting when SC0CR<PE> is set to 1 (Enabled).
Example: When receiving data of the following format, the control registers should
be set as described below.
Transmission direction (Transmission rate: 2400 bps at fc
=
12.288 MHz)
Start
Bit0
1 2 3
5
4 6
Even
parity
Stop
Transmission direction (Transmission rate: 9600 bps at fc
=
12.288 MHz)
Start Bit0 1
2
3
5
4 6
Odd
parity Stop
7