Dedicated Baud Rate Generator N (Brgn); Baud Rate Generator N (Brgn) Configuration - NEC V850ES/KE1+ User Manual

14.6 Dedicated Baud Rate Generator n (BRGn)

A dedicated baud rate generator, which consists of a source clock selector and an 8-bit programmable counter,
generates serial clocks during transmission/reception by UARTn. The dedicated baud rate generator output can be
selected as the serial clock for each channel.
Separate 8-bit counters exist for transmission and for reception.

14.6.1 Baud rate generator n (BRGn) configuration

Figure 14-16. Configuration of Baud Rate Generator n (BRGn)
f
f
f
f
XX
f
XX
f
XX
f /1,024
XX
Note 2
External input ASCK0
Notes 1. Set f so as to satisfy the following conditions.
UCLK
• V
= 4.5 to 5.5 V: f
DD
• V
= 2.7 to 4.5 V: f
DD
2. ASCK0 pin input can be used only by UART0.
Remark f : Main clock frequency
XX
f : Base clock
UCLK
(1) Base clock
When the ASIMn.UARTEn bit = 1, the clock selected according to the CKSRn.TPSn3 to CKSRn.TPSn0 bits
is supplied to the transmission/reception unit. This clock is called the base clock (f
bit = 0, f is fixed to low level.
UCLK
424
CHAPTER 14 ASYNCHRONOUS SERIAL INTERFACE (UART)
UARTEn
f
XX
f /2
XX
f /4
XX
f /8
XX
/16
XX
f
/32
UCLK
XX
Selector
/64
XX
/128
/256
/512
CKSRn: TPSn3 to TPSn0
≤ 12 MHz
UCLK
≤ 6 MHz
UCLK
User's Manual U16896EJ2V0UD
UARTEn and TXEn bits
(or RXEn bit)
Note 1
8-bit counter
Match detector
BRGCn: MDLn7 to MDLn0
1/2 Baud rate
). When the UARTEn
UCLK