UPD78F0411GA-GAM-AX Datasheet, PDF (333/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 13 SERIAL INTERFACE UART0
(2) Generation of serial clock
A serial clock to be generated can be specified by using baud rate generator control register 0 (BRGC0).
Select the clock to be input to the 5-bit counter by using bits 7 and 6 (TPS01 and TPS00) of BRGC0.
Bits 4 to 0 (MDL04 to MDL00) of BRGC0 can be used to select the division value (fXCLK0/8 to fXCLK0/31) of the 5-bit
counter.
13.4.4 Calculation of baud rate
(1) Baud rate calculation expression
The baud rate can be calculated by the following expression.
•
fXCLK0
Baud rate =
[bps]
2×k
fXCLK0: Frequency of base clock selected by the TPS01 and TPS00 bits of the BRGC0 register
k:
Value set by the MDL04 to MDL00 bits of the BRGC0 register (k = 8, 9, 10, ..., 31)
TPS01
0
0
1
1
TPS00
0
1
0
1
Table 13-4. Set Value of TPS01 and TPS00
Base clock (fXCLK0) selection^{Note 1}
fPRS = 2 MHz
TM50 output^{Note 2}
fPRS = 5 MHz
fPRS = 8 MHz fPRS = 10 MHz
fPRS/2
fPRS/2³
fPRS/2⁵
1 MHz
250 kHz
62.5 kHz
2.5 MHz
625 kHz
156.25 kHz
4 MHz
1 MHz
250 kHz
5 MHz
1.25 MHz
312.5 kHz
Notes 1.
2.
If the peripheral hardware clock (fPRS) operates on the high-speed system clock (fXH) (XSEL = 1), the
fPRS operating frequency varies depending on the supply voltage.
• VDD = 2.7 to 5.5 V: fPRS ≤ 10 MHz
• VDD = 1.8 to 2.7 V: fPRS ≤ 5 MHz
When selecting the TM50 output as the base clock, start the operation of 8-bit timer/event counter 50
first and then enable the timer F/F inversion operation (TMC501 = 1).
(2) Error of baud rate
The baud rate error can be calculated by the following expression.
Actual baud rate (baud rate with error)
• Error (%) =
− 1 × 100 [%]
Desired baud rate (correct baud rate)
User’s Manual U18698EJ1V0UD
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