R01UH0092EJ0110 Rev.1.10
Page 508 of 807
Jul 31, 2012
M16C/64C Group
23. Serial Interface UARTi (i = 0 to 2, 5 to 7)
Figure 23.34 Bus Collision Detect Function-Related Bits
(1) ABSCS bit in UiSMR register (bus collision detect sampling clock select)
When ABSCS is 0, bus collision is determined at the rising edge of the transmit/receive clock.
Transmit/receive clock
Timer Aj
(2) ACSE bit in UiSMR register (transmit enable bit automatically cleared)
IR bit in registers
UiBCNIC and BCNIC
TE bit in the UiC1
register
(3) SSS bit in the UiSMR register (transmit start condition select)
TXDi
Transmit enable conditions are met.
CLKi
TXDi
RXDi
Notes:
1. The falling edge of RXDi when the IOPOL bit in the UiMR register is 0; the rising edge of RXDi when the IOPOL bit is 1.
2. The transmit conditions must be met before the falling edge of RXD.
When the SSS bit is 0, the serial interface starts sending data one transmit/receive clock cycle after the transmission
start condition is met.
TXDi
RXDi
ST
D0
D1
D2
D3
D4
D5
D6
D7
D8
SP
Trigger signal is applied to the TAjIN pin
When ABSCS is 1, bus collision is determined when timer Aj (one-shot timer mode) underflows.
Transmit/receive clock
TXDi
RXDi
ST
D0
D1
D2
D3
D4
D5
D6
D7
D8
SP
Transmit/receive clock
ST
D0
D1
D2
D3
D4
D5
D6
D7
D8
SP
ST
D0
D1
D2
D3
D4
D5
D6
D7
D8
SP
When the SSS bit is 1, the serial interface starts sending data at the rising edge of RXDi.
(1)
(2)
When the ACSE bit is 1 (auto
clear at bus collision), the TE bit
is cleared to 0.
(transmission disabled) when the
IR bit in the UiBCNIC register is 1
(unmatching detected).
The above diagram applies when IOPOL is 1 (reversed).
(i = 0 to 2, 5 to 7)
i = 0 to 2, 5 to 7
Timer Aj: Timer A3 in UART0; timer A4 in UART1; timer A0 in UART2
timer A0 in UART5; timer A3 in UART6; timer A4 in UART7
Содержание M16C Series
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