CDPD Wireless Modem Data Pump

FX949

© 1996 Consumer Microcircuits Limited

9

D/949/5

1.5

General Description

This device performs most of the Medium Access Control (MAC) layer functions of the CDPD

specification as well as generation of the baseband signals in the physical layer, all of which are

specifically for the Mobile End Station (M-ES). For details of the system requirements and telegram

formats, the user is referred to "Cellular Digital Packet Data System Specification", Volumes 1 to 5,

currently available from:

CDPD Forum Inc.

PO Box 809320

Chicago, IL 60686

United States of America

1.5.1

Software Description

From the programmer's viewpoint, the FX949 interface consists of a number of registers, addressable

from a 7-bit bus with data supplied on a standard 8-bit

µP bus, as shown in Figure 4.

Read Only Registers

A0 - A6

HEX

ADDRES

S

RDN

WRN

CSN

REGISTER

NAME

BIT 7

(D7)

BIT 6

(D6)

BIT 5

(D5)

BIT 4

(D4)

BIT 3

(D3)

BIT 2

(D2)

BIT 1

(D1)

BIT 0

(D0)

$00

0

1

0

RX DATA 0

0

0

<-------------------- DATA SYMBOL 0 ------------------>

$01

0

1

0

RX DATA 1

0

0

<-------------------- DATA SYMBOL 1 ------------------>

$02

0

1

0

RX DATA 2

0

0

<-------------------- DATA SYMBOL 2 ------------------>

|

|

|

|

|

|

|

|

|

|

|

|

$3C

0

1

0

RX DATA 60

0

0

<------------------ DATA SYMBOL 60 ------------------->

$3D

0

1

0

RX DATA 61

0

0

<------------------ DATA SYMBOL 61 ------------------->

$3E

0

1

0

RX DATA 62

0

0

<------------------ DATA SYMBOL 62 ------------------->

$3F

0

1

0

RX SYN 1

0

0

<-- SYNDROME SYMBOL 1

= [ r (x) / (x +

α1) ] ---

>

$40

0

1

0

RX SYN 2

0

0

<-- SYNDROME SYMBOL 2

= [ r (x) / (x +

α2) ] ---

>

$41

0

1

0

RX SYN 3

0

0

<-- SYNDROME SYMBOL 3

= [ r (x) / (x +

α3) ] ---

>

$42

0

1

0

RX SYN 4

0

0

<-- SYNDROME SYMBOL 4

= [ r (x) / (x +

α4) ] ---

>

$43

0

1

0

RX SYN 5

0

0

<-- SYNDROME SYMBOL 5

= [ r (x) / (x +

α5) ] ---

>

$44

0

1

0

RX SYN 6

0

0

<-- SYNDROME SYMBOL 6

= [ r (x) / (x +

α6) ] ---

>

$45

0

1

0

RX SYN 7

0

0

<-- SYNDROME SYMBOL 7

= [ r (x) / (x +

α7) ] ---

>

$46

0

1

0

RX SYN 8

0

0

<-- SYNDROME SYMBOL 8

= [ r (x) / (x +

α8) ] ---

>

$47

0

1

0

RX SYN 9

0

0

<-- SYNDROME SYMBOL 9

= [ r (x) / (x +

α9) ] ---

>

$48

0

1

0

RX SYN 10

0

0

<-- SYNDROME SYMBOL 10 = [ r (x) / (x +

α10) ] --

>