Functional Description; Table 6.12.4-1 Uart Interface Controller Pin; Table 6.12.5-1 Uart Controller Baud Rate Equation Table - Nuvoton ISD94124BYI Technical Reference Manual

UART0_TXD Output
UART0_RXD Input
UART0_nCTS Input
UART0_nRTS Output

6.12.5 Functional Description

The ISD94100 series UART controller supports four function modes including UART and RS-485.
The current function mode is selected by UART_FUNCSEL register.
6.12.5.1 UART Controller Baud Rate Generator
The ISD94100 series device integrates a programmable baud rate generator.
Table 6.12.5-1 describes the baud-rate calculation. Table 6.12.5-2 and Table 6.12.5-3 gives a quick
reference for available baud rates under different mode and BRD setting. In these table:
-
There are three modes for baud rate setting. Baud rate mode is defined by BAUDM0 and
BAUDM1 bits (UART_BAUD[29:28]).
-
BRD value in the formula is defined by BRD bits in register UART_BAUD[15:0].
BAUDM0 BAUDM1
Mode
Mode 0
0
Mode 1 0
Mode 2 1

Table 6.12.5-1 UART controller Baud Rate Equation Table

Baud Rate
921600
Sep 9, 2019
ISD94100 Series Technical Reference Manual
UART0 transmit
UART0 receive
UART0 modem clear to send
UART0 modem request to send

Table 6.12.4-1 UART Interface Controller Pin

Baud Rate Equation
0 UART0_CLK / [16 * (BRD+2)].
1 UART0_CLK / [(EDIVM1+1) * (BRD+2)], EDIVM1 must >= 8.
UART0_CLK / (BRD+2)
If UART0_CLK <= 3*HCLK, BRD must >= 9.
If UART0_CLK > 3*HCLK, BRD must >= 3*N – 1.
N is the smallest integer larger than or equal to the ratio of UART0_CLK /HCLK.
1
For example,
if 3*HCLK < UART0_CLK =< 4*HCLK, BRD must >=11.
if 4*HCLK < UART0_CLK =< 5*HCLK, BRD must >=14.
(If the UART0_CLK is selected from LXT, BRD can be greater than or equal to 1)
UART Peripheral Clock = 12 MHz
Mode 0
Not support
Page 571 of 928
Mode 1
Not recommended
Mode 2
BRD=11
Rev1.09