R01UH0136EJ0210 Rev.2.10
Page 480 of 800
Jul 31, 2012
M16C/64A Group
23. Serial Interface UARTi (i = 0 to 2, 5 to 7)
Figure 23.12 Transmit Timing in UART Mode
D0
D1
D2
D3
D4
D5
D6
D7
ST
P
Parity
bit
TXDi
CTSi
0
1
0
1
High
0
1
Tc = 16(n + 1)/fj or 16(n + 1)/fEXT
fj: Frequency of UiBRG count source (f1SIO, f2SIO,
f8SIO, f32SIO)
fEXT: Frequency of UiBRG count source (external clock)
n: Value set to UiBRG
0
1
Set to 0 by an interrupt request acknowledgment or by a program.
D0
D1
D2
D3
D4
D5
D6
D7
ST
P
D0
D1
ST
TXDi
0
1
0
1
0
1
Transmit/
receive clock
Tc
0
1
Set to 0 by an interrupt request acknowledgment or by a program.
Tc
Transmit/receive
clock
Stop
bit
Set the data in the UiTB register.
Data is transferred from the UiTB
register to the UARTi transmit register.
Start bit
D0
D1
D2
D3
D4
D5
D6
D7
ST
D8
D0
D1
D2
D3
D4
D5
D6
D7
ST
D8
D0
D1
ST
SP SP
Stop
bit
The transmit/receive clock stops once because a high-level signal is applied to
the CTS pin when the stop bit is verified. The transmit/receive clock resumes
running as soon as a low-level signal is applied to the CTS pin.
Set the data in the UiTB register.
SP
Data is transferred from the UiTB register
to the UARTi transmit register.
Stop
bit
TE bit in the
UiC1 register
TI bit in the
UiC1 register
TXEPT bit in the
UiC0 register
IR bit in the
SiTIC register
TE bit in the
UiC1 register
TI bit in the
UiC1 register
TXEPT bit in the
UiC0 register
IR bit in the
SiTIC register
Low
Pulse stops because the TE
bit is 0.
SP
SP
Start bit
SP
TC = 16(n + 1)/fj or 16(n + 1)/fEXT
fj: Frequency of UiBRG count source (f1SIO, f2SIO,
f8SIO, f32SIO)
fEXT: Frequency of UiBRG count source (external clock)
n: Value set to UiBRG
(1) 8-bit Data Transmit Timing (with a Parity Bit and 1 Stop Bit)
(2) 9-bit Data Transmit Timing (with No Parity Bit and 2 Stop Bits)
i = 0 to 2, 5 to 7
The above assumes the following:
• The PRYE bit in the UiMR register is 1 (parity enabled).
• The STPS bit in the UiMR register is 0 (1 stop bit).
• The CRD bit in the UiC0 register is 0 (
CTS
/
RTS
enabled)
• The CRS bit in the UiC0 register is 0 (
CTS
selected).
• The UiIRS bit in the UiC1 or UCON register is 1
(an interrupt request occurs when transmit completed)
i = 0 to 2, 5 to 7
The above assumes the following:
• The PRYE bit in the UiMR register is 0 (parity disabled).
• The STPS bit in the UiMR register is 1 (two stop bit).
• The CRD bit in the UiC0 register is 1 (
CTS
/
RTS
disabled)
• The UiIRS bit in the UiC1 or UCON register is 0
(an interrupt request occurs when transmit buffer becomes empty)
Содержание M16C/60 Series
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