FM214 ETC [List of Unclassifed Manufacturers], FM214 Datasheet - Page 7

• Manufacturer Part Number: FM214
• Description: 9600/14400 BPS MONOFAX MODEM FAMILY
• Manufacturer: ETC [List of Unclassifed Manufacturers]

 
   
 

Software Interface
Modem functions are implemented in firmware
executing in the modem DSP. The DSP RAM interface
memory bits, access functions, codes, and registers
are defined in the Designer’s Guide.
Interface Memory
The DSP communicates with the host processor by
means of a dual-port, interface memory. This interface
memory contains thirty-two 8-bit registers, labeled
register 00h through 1Fh. Each register can be read or
written by the host and the DSP.
The host controls the modem operation by writing
control bits to DSP interface memory and writing
parameter values to DSP RAM through interface
memory. The host monitors the modem operation by
reading status bits from DSP interface memory and
reading parameter values from DSP RAM through
interface memory. An interface memory interrupt is
provided.
DSP RAM Access
The DSP contains 16-bit word RAM. Because the DSP
is optimized for performing complex arithmetic, the
RAM is organized into real (X RAM) and imaginary (Y
RAM) parts. The host processor can read or write both
the X RAM and the Y RAM.
DSP interface memory mediates data exchange
between the host and DSP RAM. The address stored
in interface memory RAM address registers by the
host determines the DSP RAM address for data
access.
MD205
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