Lucent Technologies MN10285K User Manual
Page 134
Serial Interfaces
Serial Interface Setup Examples
MN102H75K/F75K/85K/F85K LSI User Manual
Panasonic Semiconductor Development Company
133
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Transmission sequence:
1.
Write the first data byte to SC0TRB. Once this data is in the register, trans-
mission begins, synchronized to timer 0.
2.
When an interrupt occurs, the program branches to the interrupt service rou-
tine. The routine must determine the interrupt group, then clear the interrupt
request flag.
3.
Write the next data byte to SC0TRB. Once the write is complete, transmis-
sion begins in 1 or 2 cycles of the transfer clock (timer 0 underflow).
Figure 5-10 shows an example timing chart.
Figure 5-10 UART Transmission Timing (Serial Interface 0)
TC0 underflow (1/8)
SC0TRB write
SBO0
Interrupt request
Interrupt service
routine
SC0TBSY
ST b0 b1 b2 b3 b4 b5 b6 b7 PT SP SP
ST b0 b1 b2 b3 b4