Winbond W83627DHG, Manual

Page: 155 / 268

W83627DHG
Publication Release Date: Aug, 22, 2007
-143- Version 1.4
11.2.7 Interrupt Control Register (ICR) (Read/Write)
This 8-bit register enables and disables the five types of controller interrupts separately. A selected
interrupt can be enabled by setting the appropriate bit to logical 1. The interrupt system can be totally
disabled by setting bits 0 through 3 to logical 0.
0 0 0
1
2 3 4 5 6
7
0
0
RBR data ready interrupt enable (ERDRI)
TBR empty interrupt enable (ETBREI)
UART receive status interrupt enable (EUSRI)
Handshake status interrupt enable (EHSRI)
Bit 7-4: These four bits are always logical 0.
Bit 3: EHSRI. Set this bit to logical 1 to enable the handshake status register interrupt.
Bit 2: EUSRI. Set this bit to logical 1 to enable the UART status register interrupt.
Bit 1: ETBREI. Set this bit to logical 1 to enable the TBR empty interrupt.
Bit 0: ERDRI. Set this bit to logic 1 to enable the RBR data ready interrupt.
11.2.8 Programmable Baud Generator (BLL/BHL) (Read/Write)
Two 8-bit registers, BLL and BHL, compose a programmable baud generator that uses 24 MHz to
generate a 1.8461 MHz frequency and divide it by a divisor from 1 to (2
16
–1). The output frequency of
the baud generator is the baud rate multiplied by 16, and this is the base frequency for the transmitter
and receiver. The table below illustrates the use of the baud generator with a frequency of 1.8461
MHz. In high-speed UART mode (CR0C, bits 7 and 6), the programmable baud generator directly uses
24 MHz and the same divisor as the normal speed divisor. As a result, in high-speed mode, the data
transmission rate can be as high as 1.5M bps.
BAUD RATE FROM DIFFERENT PRE-DIVIDER
PRE-DIV: 13
1.8461M HZ
PRE-DIV:1.625
14.769M HZ
PRE-DIV: 1.0
24M HZ
DECIMAL DIVISOR
USED TO
GENERATE 16X
CLOCK
ERROR PERCENTAGE
50 400 650 2304 **
75 600 975 1536 **
110 880 1430 1047 0.18%
134.5 1076 1478.5 857 0.099%
150 1200 1950 768 **
300 2400 3900 384 **
600 4800 7800 192 **
1200 9600 15600 96 **
1800 14400 23400 64 **
2000 16000 26000 58 0.53%