NEC uPD78P078 User Manual
Page 492
492
CHAPTER 20 SERIAL INTERFACE CHANNEL 2
Figure 20-15. Period that Reading Receive Buffer Register is Prohibited
T1 : The amount of time for one unit of data sent in the baud rate selected with the baud
rate generator control register (BRGC) (1/baud rate)
T2 : The amount of time for 2 clocks of 5-bit counter source clock (f
SCK
) selected with
BRGC
Example of countermeasures
An example of the countermeasures is shown below.
[Condition]
f
X
= 5.0 MHz
Processor clock control register (PCC) = 00H
Oscillation mode selection register (OSMS) = 01H
Baud rate generator control register (BRGC) = B0H (when 2400 bps is selected for baud rate)
T
CY
= 0.4
µ
s (t
CY
= 0.2
µ
s)
1
T1 =
= 416.7
µ
s
2400
T2 = 12.8 x 2 = 25.6
µ
s
T1 + T2
= 2212 (clock)
t
CY
RxD (input)
INTSR
INTSER (when framing or
overrun error is generated)
INTSER (when parity error
is generated)
D0
T1
T2
D1
D2
D6
D7
STOP
START
Parity