TMP91C824
91C824-147
2008-02-20
*
Clock state
System clock:
High frequency (fc)
Clock gear:
1 (fc)
Prescaler clock: System clock
Main settings
7 6 5 4 3 2 1 0
PCCR
←
X X
−
−
− −
0
−
Set PC1 to function as the RXD0 pin.
SC0MOD0
←
−
−
1
−
1 0 0 1
Enable receiving in 8-bit UART mode.
SC0CR
←
−
0 1
−
− − − −
Add
even
parity.
BR0CR
←
0 0 0 1 0 1 0 1
Set the transfer rate to 9600 bps.
INTES0
←
−
−
−
−
−
1 0 0
Enable the INTTX0 interrupt and set it to interrupt level 4.
Interrupt processing
Acc
←
SC0CR AND 00011100
if Acc
≠
0 then ERROR
Check for errors.
Acc
←
SC0BUF
Read the received data.
X: Don’t care,
−
: No change
(4)
Mode 3 (9-bit UART mode)
9-bit UART mode is selected by setting SC0MOD0<SM1:0> to 11. In this mode
parity bit cannot be added.
In the case of transmission the MSB (9th bit) is written to SC0MOD0<TB8>. In the
case of receiving it is stored in SC0CR<RB8>. When the buffer is written and read,
the MSB is read or written first, before the rest of the SC0BUF data.
Wakeup function
In 9-bit UART mode, the wakeup function for slave controllers is enabled by setting
SC0MOD0<WU> to 1. The interrupt INTRX0 occurs only when<RB8>
=
1.
Note: The TXD pin of each slave controller must be in Open-drain output mode.
Figure 3.9.23 Serial Link Using Wakeup Function
TXD
Master
Slave 1
Slave 2
Slave 3
RXD TXD
RXD
TXD
TXD
RXD
RXD