DM336P Davicom Semiconductor Incorporated, DM336P Datasheet - Page 8

• Manufacturer Part Number: DM336P
• Manufacturer: Davicom Semiconductor Incorporated

DM6383 Functional Description
1. Operating Mode Selection
The DM6383 MCU can be used with both internal and
external modems. When it works within an internal
modem, pin TEST2 and TEST1 must be in a low state.
The DM6383 includes a virtual UART and supports a
parallel interface.
When DM6383 works within an external modem, pin
TEST2 must be in a low state, and pin TEST1 must
be in high. The virtual UART will be disabled and the
RS232 serial interface, enabled.
2. Micro-controller (80C31) Reference
DM6383 supports a bank switch control pin to switch
external program memory between lower 64K bytes
(bank 0) and upper 64K bytes (bank 1) of 27C010.
In this mode, two instructions must be included in
software to switch bank 0 to bank 1:
i.e.,
With the same way, it can also switch back to bank 0
by
* For detailed information about micro-controller,
3. Micro-controller Register Description
a. UART Clock Register :
Write Only
8
bit7
please see Programmer's Guide to 8031.
TEST2
HIGH
LOW
LOW
Address D4000H Reset State: 06H
X
dat6 dat5 dat4 dat3 dat2 dat1
bit6
CLR
JMP
SETB
JMP
TEST1
HIGH
LOW
bit5
X
P1.3
BANK 1 ADDRESS
P1.3
BANK 0 ADDRESS
bit4
System Configuration
bit3
External Modem
Internal Modem
V.34 Integrated Data/ Fax/Voice/Speakerphone Modem Device Set
Test Mode
bit2
bit1
bit0
0
The clock source of the virtual UART logic is fixed at
1.8432MHz. The clock is derived from the external
crystal used by the DM6383 controller. Therefore, the
UART 1.8432MHz clock must be obtained through
division. When the operating frequency of the
DM6383 controller changes, the divider should be
changed accordingly. This divider is specified by the
Configuration Register which can be written by the
DM6383 controller. The address mapping of the
register is D4000H: (DM6383 controller memory
mapping)
Bit 0: Always 0.
Bit 6-1: B6 - B1 define the clock di vider range from 2
Bit 7: Not used.
b. UART Baud Generator Divisor Latch Register:
Read only
By reading this register, the micro-controller can
monitor the value of the low byte divisor latch of the
virtual UART baud generator (see DLL in next section)
and determine the baud rate clock itself.
c. Modem Status Controller Register (MSCR):
Write only
The advantage of this register is that the modem line
status information can be passed to the virtual UART
by the micro-controller. The resulting signals are Ring
Detect (/RI), Carrier Detect (/DCD), Data Set Ready
(/DSR) and Clear To Send (/CTS).
dat7 dat6 dat5 dat4 dat3 dat2 dat1 dat0
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
bit7 bit6 bit5 bit4 bit3 bit2
Address EC00H
Address E000H
0
to 64 (even number).
0
0
0
/CTS /DSR /DCD /RI
Version: DM336P-DS-F02
DM336P
bit1 bit
August 15, 2000
0
Final