
Figure 16.43
Transmit Operation in UART mode
SP
Serial Clock
(1) 8-bit data transmit timing (parity enabled and 1 stop bit)
TC = 16 (m + 1) / fj or 16 (m + 1) / fEXT
fj: Count source frequency set in the UiBRG register (f1, f8, f2n(1))
fEXT: Count source frequency set in the UiBRG register (external clock)
m: Setting value of the UiBRG register
1
0
The above applies under the following conditions:
- PRYE bit in UiMR register = 0 (parity disabled)
- STPS bit in UiMR register = 1 (2 stop bits)
- CRD bit in UiC0 register = 1 (CTS function disabled)
- UilRS bit in U56CON register = 0 (interrupt request generated
when no data in the UiTB register)
1
0
(2) 9-bit data transmit timing (parity disabled and 2 stop bits)
TE bit in
UiC1 register
TI bit in
UiC1 register
Input to CTSi
Output
from TXDi
i = 5, 6
The above applies under the following conditions:
- PRYE bit in UiMR register = 1 (parity enabled)
- STPS bit in UiMR register = 0 (1 stop bit)
- CRD bit in the UiC0 register = 0 (CTS function enabled)
and CRS bit = 0 (CTS function selected)
- UilRS bit in U56CON register = 1 (interrupt request generated
when transmit operation completed)
Set to 0 by an interrupt request acknowledgement or by program
Stop
bit
TC
Data is set in the UiTB register
ST
D6
D7
P
TC = 16 (m + 1) / fj or 16 (m + 1) / fEXT
fj: Count source frequency set in the UiBRG register (f1, f8, f2n(1))
fEXT: Count source frequency set in the UiBRG register (external clock)
m: Setting value of the UiBRG register
NOTE:
1. Bits CNT3 to CNT0 in the TCSPR register select either no division (n = 0)
or divide-by-2n (n = 1 to 15).
ST
D0
D1
D2
D3
D4
D5
D6
D7
D8
Data is set in the UiTB register
Data is transferred from the UiTB register
to the UARTi transmit register
Set to 0 by an interrupt request acknowledgement or by program
Serial Clock
TE bit in
UiC1 register
TI bit in
UiC1 register
Output
from TXDi
TXEPT bit in
UiC0 register
ST
D0
D1
D2
D3
D4 D5
ST
D0
D1
Parity
bit
Start
bit
D0
D1
D2
D3
D4
D5
D6
D7
D8
D1
D0
ST
Start
bit
The serial clock stops momentarily, because an "H" signal is applied to theCTS pin,
when the stop bit is verified.
The serial clock resumes running as soon as an "L" signal is applied to theCTS pin.
TC
ST
"H"
"L"
D0
D1
D2
D3
D4
D5
D6
D7
P
Communication stops because
the TE bit is set to 0
SP SP
Data is transferred from the UiTB register
to the UARTi transmit register
1
0
1
0
1
0
1
0
1
0
1
0
Stop
bit
SP SP
U5TR bit in
IIO1IR register or
U6TR bit in
IIO10IR register
SP
TXEPT bit in
UiC0 register
U5TR bit in
IIO1IR register or
U6TR bit in
IIO10IR register