73K222BL

V.22, V.21, Bell 212A, Bell 103

Single-Chip Modem with Integrated Hybrid

8

REGISTER DESCRIPTIONS

Four 8-bit internal registers are accessible for

control and status monitoring. The registers are

accessed

in

read

or

write

operations

by

addressing AD0, AD1 and AD2 lines. The address

lines are latched by ALE. Register CR0 controls

the method by which data is transferred over the

phone line. CR1 controls the interface between the

microprocessor and the 73K222BL internal state.

DR is the Detect Register which provides an

indication of monitored modem status conditions.

TR, the Tone Control Register, controls the DTMF

generator, answer and guard tones and RXD

output gate used in the modem initial connect

sequence. All registers are read/write except for

DR which is read only. Register control and status

bits are identified below:

REGISTER BIT SUMMARY

NOTE:

When a register containing reserved control bits is written into, the reserved bits must be

programmed as 0's.

X = Undefined, mask in software

MODULATION

OPTION

00 = NORMAL

01 = ANALOG LOOPBACK

10 = REMOTE DIGITAL

LOOPBACK

11 = LOCAL DIGITAL

LOOPBACK

CONTROL

REGISTER

000

TRANSMIT

MODE

3

TRANSMIT

MODE

2

TRANSMIT

MODE

1

TRANSMIT

ENABLE

ORIGINATE/

ANSWER

DATA BIT NUMBER

AD2 - AD0

REGISTER

ADDRESS

D7

D6

D5

D4

D3

D2

D1

D0

TEST

MODE

0

TEST

MODE

1

RESET

CLK

CONTROL

BYPASS

SCRAMBLER

ENABLE

DETECT

INTERRUPT

TRANSMIT

PATTERN

0

TRANSMIT

PATTERN

1

001

CONTROL

REGISTER

CR1

LONG

LOOP

CALL

PROGRESS

ANSWER

TONE

CARRIER

DETECT

RECEIVE

DATA

010

DETECT

REGISTER

DR

DTMF0/

GUARD/

ANSWER/

TONE

DTMF1/

OVERSPEED

DTMF2

DTMF3

TRANSMIT

DTMF

TRANSMIT

ANSWER

TONE

RXD

OUTPUT

CONTROL

011

TONE

CONTROL

REGISTER

TR

TRANSMIT

MODE

0

0000 = PWR DOWN

0001 = INT SYNCH

0010 = EXT SYNCH

0011 = SLAVE SYNCH

0100 = ASYNCH 8 BITS/CHAR

0101 = ASYNCH 9 BITS/CHAR

0110 = ASYNCH 10 BITS/CHAR

0111 = ASYNCH 11 BITS/CHAR

1100 = FSK

0 = DISABLE

TXA OUTPUT

1 = ENABLE

TXA OUTPUT

0 = ANSWER

1 = ORIGINATE

00 = TX DATA

01 = TX ALTERNATE

10 = TX MARK

11 = TX SPACE

0 = DISABLE

1 = ENABLE

0 = NORMAL

1 = BYPASS

SCRAMBLER

0 = XTAL

1 = 16 X DATA

RATE OUTPUT

AT CLK PIN IN

DPSK MODE

ONLY

0 = NORMAL

1 = RESET

OUTPUTS

RECEIVED

DATA STREAM

0 = CONDITION NOT DETECTED

1 = CONDITION DETECTED

RXD PIN

0 = NORMAL

1 = WEAK PULL-UP

0 = OFF

1 = ON

0 = Disable DTMF

1 = TX DTMF

4 BIT CODE FOR 1 OF 16

DUAL TONE COMBINATIONS

CR0

0 = 1200 BIT/S DPSK

1 = 600 BIT/S DPSK

0 = BELL 103 FSK

1 = V.21 FSK

TRANSMIT

GUARD/

TONE

0 = 2225 Hz A.T.

1800 Hz G.T.

1 = 2100 Hz A.T.

500 Hz G.T.

0 = OFF

1 = ON

UNSCR.

MARKS

ID

REGISTER

10

110

1

0

X

OH

0

X

X

XX

XX

X = Undefined, mask in software

0 = OH Relay driver open

1 = OH Open drain driver pulling low

1

0

00XX = 73K212AL, 322L, 321L

01XX = 73K221AL, 302L

10XX = 73K222AL, 222BL

1100 = 73K224L, 224BL

1110 = 73K324L, 324BL