2.0 Hardware Interface
RC224ATL/224ATLV
2.2 Additional Information
EmbeddedModem Family
Divisor Registers
(Addr=0 and 1, DLAB=1)
The Divisor Latch LS Byte and Divisor Latch MS Byte are two read-write
registers at locations 0 and 1 when DLAB = 1, respectively.
The baud rate is selected by loading each divisor latch with the appropriate
hex value. Table 2-2 lists the programmable values corresponding to the desired
baud rate.
Table 2-2. Programmable Baud Rates
Divisor Latch (Hex)
Divisor
Baud Rate
(Decimal)
MS
LS
01
00
00
00
80
C0
60
30
384
192
96
300
600
1200
2400
48
Scratch Register (SCR)
(Addr = 7)
The Scratchpad Register is a read-write register at location 7. This register is not
used by the DSP and can be used by the host for temporary storage.
2.1.2 Serial/Indicator Interface
A DTE serial interface and indicator outputs are supported.
•
Serial Interface: An 8-line V.24/EIA-232-D or TTL logic serial interface to
the DTE is supported.
•
LED Indicator Interface: Four direct connect LED indicator outputs are
supported.
2.1.3 Speaker Interface
A speaker output, controlled by AT or V.25 bis commands, is provided for an
optional OEM-supplied speaker circuit.
2.1.4 Line Interface
The EmbeddedModem connects to the line interface circuitry by means of a
receive analog input, two transmit analog outputs, and a ring signal input.
The EmbeddedModem provides three relay control outputs to the line
interface. These outputs may be used to control relays such as off-hook, A/A1,
and talk/data.
2.2 Additional Information
Additional information is provided in the RC224ATLV Modem Designer’s Guide
(Order No. 821).
2-12
Conexant
D224ATLVDSC
CONEXANT [ CONEXANT SYSTEMS, INC ]
