mcs7717 MosChip, mcs7717 Datasheet - Page 26

• Manufacturer Part Number: mcs7717
• Description: Three Port Usb Hub With 1 Serial, 1 Printer
• Manufacturer: MosChip

Page 26
MCS7717
Three Port USB Hub with 1 Serial, 1 Printer
Divisor Latch Registers:
The divisor latch registers (DLL & DLM) are used to program the baud rate divisor. This is a value between 1
and 65535 by which the input clock is divided in order to generate serial Baud Rates. After a hardware Reset,
the Baud Rate used by the transmitter & receiver is given by:
where divisor is given by: (256 * DLM ) + DLL
Note: More flexible Baud Rate generation options are also available. These require the use of Advanced
Features in other registers however.
Register:
Description:
Offset:
Permissions:
Access Condition:
Register:
Description:
Offset:
Permissions:
Access Condition:
Baud Rate = Input Clock / 16 * Divisor
Bit[7]
Bit[7]
Baud Rate Generator
Programming Table
DLL
Divisor Latch Register
000
Read/Write
LCR[7] =1, Address = 000
DLM
Divisor Latch Register
001
Read/Write
LCR[7] =1, Address = 001
Bit[6]
Bit[6]
Bit[5]
Bit[5]
Least significant Byte for divisor latch
Most significant Byte for divisor latch
Bit[4]
Bit[4]
Bit[3]
Bit[3]
Baud Rate
115.2K
57.6K
38.4K
19.2K
9600
2400
1200
600
300
150
50
Bit[2]
Bit[2]
(Hex)
DLM
Bit[1]
Bit[1]
00
00
00
00
00
00
00
00
01
03
09
(Hex)
Bit[0]
Bit[0]
DLL
Rev. 1.7
0C
C0
01
02
03
06
30
60
80
00
00