M32C80 Datasheet, PDF (206/352 Pages) Renesas Technology Corp – 16/32-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M32C/80 SERIES

M32C/80 Group
16. Serial I/O (UART)
8-bit Data Receive Timing (with no parity and 1 stop bit)
UiBRG register
setting output
RE bit in the
"1"
UiC1 register
"0"
RxDi
Start bit
D0
D1 D7
Verify if an "L"
signal is applied
Capture a received data
Stop bit
Transfer Clock
Start receiving when the transfer clock is Data is transferred from the UARTi receive
RI bit in the UiC1 ^{"1" generated on the falling edge of the start bit register to the UiRB register}
register
"0"
RTSi
"H"
"L"
Change to "L" by reading the UiRB register
IR bit in the SiRIC _"1"
register
"0"
Set to "0" by an interrupt request acknowledgement or by program
i=0 to 4
NOTE:
1. The above applies when the PRYE bit in the UiMR register is set to "0" (parity disabled),
the STPS bit in the UiMR register is set to "0" (1 stop bit) and the CRS bit in the UiC0 register is set
to "1" (RTS function selected).
Figure 16.15 Receive Operation
16.2.1 Bit Rate
In UART mode, bit rate is clock frequency which is divided by a setting value of the UiBRG (i=0 to 4)
register and again divided by 16. Table 16.11 lists an example of bit rate setting.
Table 16.11 Bit Rate
Bit Rate
(bps)
Count
Source
of
UiBRG
Peripheral Function Clock:
16MHz
Setting Value Actual Bit Rate
of UiBRG: n
(bps)
Peripheral Function Clock:
24MHz
Setting Value Actual Bit Rate
of UiBRG: n
(bps)
Peripheral Function Clock:
32MHz
Setting Value Actual Bit Rate
of UiBRG: n
(bps)
1200 f8
103 (67h)
1202
155 (96h)
1202
207 (CFh)
1202
2400 f8
51 (33h)
2404
77 (46h)
2404
103 (67h)
2404
4800 f8
25 (19h)
4808
38 (26h)
4808
51 (33h)
4808
9600
f1
103 (67h)
9615
155 (96h)
9615
207 (CFh)
9615
14400
f1
68 (44h)
14493
103 (67h)
14423
138 (8Ah)
14388
19200
f1
51 (33h)
19231
77 (46h)
19231
103 (67h)
19231
28800
f1
34 (22h)
28571
51 (33h)
28846
68 (44h)
28986
31250
f1
31 (1Fh)
31250
47 (2Fh)
31250
63 (3Fh)
31250
38400
f1
25 (19h)
38462
38 (26h)
38462
51 (33h)
38462
51200
f1
19 (13h)
50000
28 (1Ch)
51724
38 (26h)
51282
Rev. 1.00 Nov. 01, 2005 Page 187 of 330
REJ09B0271-0100