Section 16 Serial Communication Interface with FIFO (SCIF)
Rev. 5.00 May 29, 2006 page 482 of 698
REJ09B0146-0500
5.
TEND Flag and TE Bit Processing
The TEND flag is set to 1 during transmission of the stop bit of the last data. Consequently, if
the TE bit is cleared to 0 immediately after setting of the TEND flag has been confirmed, the
stop bit will be in the process of transmission and will not be transmitted normally. Therefore,
the TE bit should not be cleared to 0 for at least 0.5 serial clock cycles (or 1.5 cycles if two
stop bits are used) after setting of the TEND flag setting is confirmed.
6.
Receive Data Sampling Timing and Receive Margin
The SCIF operates on a base clock with a frequency of 16 times the transfer rate. In reception,
the SCIF synchronizes internally with the fall of the start bit, which it samples on the base
clock. Receive data is latched at the rising edge of the eighth base clock pulse. The timing is
shown in figure 16.13.
0 1 2 3 4 5 6 7 8 9 10111213 1415 0 1 2 3 4 5 6 7 8 9 10111213 1415 0 1 2 3 4 5
Base clock
Receive data
(RxD2)
Synchronization
sampling timing
Data sampling
timing
8 clocks
16 clocks
Start bit
–7.5 clocks
+7.5 clocks
D0
D1
Figure 16.13 Receive Data Sampling Timing in Asynchronous Mode
The receive margin in asynchronous mode can therefore be expressed as shown in equation 1.
Equation 1:
M = 0.5 –
1
2N
D – 0.5
N
– (L – 0.5) F – (1 + F)
×
100%
M: Receive margin (%)
N: Ratio of clock frequency to bit rate (N = 16)
D: Clock duty cycle (D = 0 to 1.0)
L: Frame length (L = 9 to 12)
F: Absolute deviation of clock frequency
Summary of Contents for SH7706 Series
Page 8: ...Rev 5 00 May 29 2006 page viii of xlviii ...
Page 160: ...Section 5 Cache Rev 5 00 May 29 2006 page 112 of 698 REJ09B0146 0500 ...
Page 370: ...Section 11 Watchdog Timer WDT Rev 5 00 May 29 2006 page 322 of 698 REJ09B0146 0500 ...
Page 554: ...Section 17 Pin Function Controller PFC Rev 5 00 May 29 2006 page 506 of 698 REJ09B0146 0500 ...
Page 576: ...Section 18 I O Ports Rev 5 00 May 29 2006 page 528 of 698 REJ09B0146 0500 ...
Page 746: ...Index Rev 5 00 May 29 2006 page 698 of 698 REJ09B0146 0500 ...
Page 749: ...SH7706 Group Hardware Manual ...