NEC PD78081(A) User Manual page 190

When the internal clock is used as the serial clock in the 3-wire serial I/O mode, set BRGC as described below.
BRGC Setting is not required if an external serial clock is used.
(i) When the baud rate generator is not used:
Select a serial clock frequency with TPS0-TPS3. Be sure then to set MDL0 to MDL3 to 1,1,1,1.
The serial clock frequency becomes the same as the source clock frequency for the 5-bit counter.
(ii) When the baud rate generator is used:
Select a serial clock frequency with TPS0-TPS3. Be sure then to set MDL0 to MDL3 to 1,1,1,1.
The serial clock frequency is calculated by the following formula:
Serial clock frequency=
Remarks 1. f
X
2. f
XX
3. n
4. k
CHAPTER 11 SERIAL INTERFACE CHANNEL 2
f
XX
[H ]
z
n
2 x (k + 16)
: Main system clock oscillation frequency
: Main system clock frequency (f
: Value set in TPS0 to TPS3 (1
: Value set in MDL0 to MDL3 (0
or f /2)
X X
n 11)
k 14)
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