Winbond Electronics W91F822N, W91F822AN, W91F820N, W91F820LN, W91F820AN Datasheet

Preliminary W91F820N SERIES

13-FLASH MEMORY TON/PULSE DIALER WITH

HANDFREE, LOCK AND HOLD FUNCTIONS

GENERAL DESCRIPTION

The W91F820N is a series of tone/pulse switchable telephone dialers with 13-flash memory, keytone,
hold, lock, and handfree dialing control features. These chips are fabricated using Winbond's high­performance CMOS technology and thus offer good performance in low-voltage, low-power
operations.

FEATURES

• Tone/pulse switchable dialer

• Two by 32 digits redial and save memory

• Three by 32 digits one-touch direct repertory flash memory

• Ten by 32 digits one-touch direct or two-touch indirect repertory flash memory

• The read-write times: 10

• Pulse-to-tone (*/T) keypad for long distance call operation

• Chain dialing

• Uses 5 × 5 keyboard

• Easy operation with redial, flash, pause, and */T keypads

• Pause, P→T (pulse-to-tone) can be stored as a digit in memory

• Dialing rate:10 ppS or 20 pps by mask option

• Minimum tone output duration: 93 mS

• Minimum intertone pause: 93 mS

• Pause time: 3.6 sec.

• Flash break time (73 mS, 100 mS, 300 mS, or 600 mS) selectable by keypad; pause time is 1.0 S

• Make/break ratio (2:3 or 1:2) selectable by MODE pin

• Mute key for speech network mute

• No key will be accepted except the "HOLD" key when in the Hold mode

• Key tone output for valid keypad entry recognition

• On-chip power-on reset

• Uses 3.579545 MHz crystal or ceramic resonator

• 20-pin 300 mil, or 22-pin 400 mil dual-in-line plastic package

• The different dialers in the W91F820N series are shown in the following table:

4

TYPE NO. PULSE

LOCK KEY

(PPS)

W91F820N 10 ­W91F820AN 10 ­W91F820LN 10
W91F820ALN 10
W91F822N 20 ­W91F822AN 20 -

HANDFREE

TONE

√

DIALING

- 20

√ √
√
√

- - 20

-

√

√

- 20

√ √

PACKAGE

(PINS)

22

22

22

Publication Release Date: January 1999

- 1 - Revision A1

PIN CONFIGURATIONS

Preliminary W91F820N SERIES

H/P MUTE

V

T/P MUTE

LOCK

H/P MUTE

V

T/P MUTE

C2
C3

C4
KT

SS

XT
XT

W91F820N/822N

C1

C2

C3

C4

SS

XT
XT

1
2

3
4

5
6
7

8
9

10

1
2

3
4

5
6

7
8

9

10 11

20

19
18
17

16
15

14
13
12

11

W91F820LN

R4C1
R3
R2
R1
N.C.

V

DD

MODE
DTMF

DP
HKS

C2
C3
C4

KT

H/P MUTE

V

XT
XT

T/P MUTE

HFI

1
2

3
4

5
6

SS

7
8

9

10
11

22
21

20

19
18
17

16
15

14
13
12

R4C1
R3
R2
R1
N.C.
V

DD

MODE
DTMF

DP
HKS

HFO

W91F820AN/822AN

C1

20

R4

19

R3
R2

18

R1

17
16

15
14
13

12

N.C.

V

DD

MODE
DTMF

DP
HKS

C2
C3
C4

LOCK

H/P MUTE

V

XT

T/P MUTE

HFI

SS

XT

1
2

3
4

5
6
7

8
9

10
11

W91F820ALN

22

21
20

19
18
17

16
15

14
13
12

R4
R3

R2
R1

N.C.

V

DD

MODE
DTMF

DP
HKS

HFO

- 2 -

Preliminary W91F820N SERIES

XT

MUTE

MUTE

HKS

HKS

HKS

HKS

HKS

LOCK

LOCK

PIN DESCRIPTION

SYMBOL 20-PIN 22-PIN I/O FUNCTION

Column-

Row Inputs

1−4

&

17−20

1−4

&

19−22

XT 8 8 I A built-in inverter together with an inexpensive 3.579545 MHz

9 9 O Crystal oscillator output pin.

T/P

10 10 O

N.C. 16 18 - No connect

MODE 14 16 I Connecting the mode pin to VSS places the dialer in tone mode.

11 13 I

KT

(W91F820N/
F820AN/
F822N)

5 5 O The key tone output is a conventional CMOS inverter. The

5 5 I The function of this terminal is to prevent "0" dialing and "9"

(W91F820LN/
820ALN only)

I

The keyboard input is compatible with a standard 5 × 5
keyboard, an inexpensive single contact (Form A) keyboard,
and electronic input.

In normal operation, any single button can be pushed to
produce dual tone, pulses, or functions. Activation of two or
more buttons will result in no response except for a single
tone.

crystal supplies the oscillator. The oscillator stops when there
is no keypad input. The crystal frequency deviation is 0.02%.

The T/P

is a conventional CMOS N-channel open

drain output.
The output transistor turns on with a low level during a dialing

sequence (both pulse and tone mode). Otherwise, it is off.

Connecting the mode pin to VDD places the dialer in pulse
mode with an M/B ratio of 40:60.

Leaving the mode pin floating places the dialer in pulse mode
with an M/B ratio of 33.3:66.7.

The

(hook switch) input is used to sense whether the

handset is on-hook or off-hook.
In on-hook state,
In off-hook state,

= 1: chip is in sleeping mode, no operation.

= 0: chip is enabled for normal operation.

pin is pulled to VDD by internal resistor.

key tone is generated when any valid key is pressed; the KT
pin generates a 1.2 KHz square wave at 35 mS. When no key
is pressed, the KT pin remains in low state.

dialing under PABX system long distance call control. When
the first key input after reset is 0 or 9, all key inputs, including
the 0 or 9 key, become invalid and the chip generates no
output. The telephone is reinitialized by a reset.

The function of the

LOCK PIN

V

DD

Floating

V

SS

"0", "9" dialing inhibited

Normal dialing Mode

"0" dialing inhibited

pin is shown below:

FUNCTION

Publication Release Date: January 1999

- 3 - Revision A1

Preliminary W91F820N SERIES

DP

HFI

HFI

HFI

Pin Description, continued

SYM. 20-PIN 22-PIN I/O FUNCTION

H/P MUTE 6 6 I

12 14 O

DTMF 14 15 O

The H/P MUTE is a conventional inverter output. During pulse
dialing, flash break or hold period, this output is active high;
otherwise, it remains in low state.

N-channel open drain dialing pulse output.
Flash key will cause DP to be active in either tone mode or pulse

mode.
The timing diagram for pulse mode is shown in Figure 1(a, b).
During pulse dialing, this pin remains in a low state regardless of

the keypad input. In tone mode, it will output a dual or single
tone.

A detailed timing diagram for tone mode is shown in Figure 2(a,
b).

OUTPUT FREQUENCY

R1
R2
R3
R4
C1
C2
C3

Specified

697
770
852

941
1209
1336
1477

Actual

699
766
848

948
1216
1332
1472

Error %
+0.28

-0.52

-0.47

+0.74

+0.57

-0.30

-0.34

VDD, VSS 15, 7 17, 7 I

, HFO

- 11, 12 I, O Handfree control pins.

Power input pins for the dialer chip. VDD is the power and VSS is
the ground.

A low pulse on the

input pin toggles the handfree control

state. The status of the handfree control state is listed in the
following table:

INPUT

HFI
HFI
HFI

Off Hook
On Hook
On Hook

NEXT STATE

HFO

DIALING

High
Low
Low
Low
Low
High

Yes

No
Yes
Yes

No
Yes

CURRENT STATE

HOOK SW.

­On Hook
Off Hook
On Hook
Off Hook
Off Hook

The

pin is pulled to VDD by an internal resistor.

HFO

Low
High
High

­Low
High

A detailed timing diagram is shown in Figure 3.

- 4 -

BLOCK DIAGRAM

Preliminary W91F820N SERIES

XT XT

ROW

(R1 ~ R4,Vx/R5)

KEYBOARD

INTERFACE

COLUMN

(C1 ~ C4,Vss)

DTMF

D/A

CONVERTER

FUNCTIONAL DESCRIPTION

Keyboard Operation

LOCATION

LATCH

ROW & COLUMN

PROGRAMMABLE

COUNTER

HKS

HFI

READ/WRITE

COUNTER

RAM

DATA LATCH

& DECODER

SYSTEM CLOCK

GENERATOR

CONTROL

LOGIC

PULSE

CONTROL

LOGIC

LOCK

MODE

T/P MUTE

KT

DP

HFO
H/P MUTE

C1 C2 C3 C4 VSS

1 2 3 S EM1 R1
4 5 6 F4 EM2 R2
7 8 9 A EM3 R3

*/T

0 # R/P SAVE R4

F1 F2 F3 H Vx/R5

• S: Store function key

• A: Indirect repertory memory dialing function key

• H: Hold function key

• R/P: Redial and pause function key

• */T: * in tone mode and P→T key in pulse mode

• SAVE: Save function key for one-touch 32-digit memory

• M0−M9: One touch memory. The dialing number can be stored in M0−M9 locations by the S key.

Note that the two touch memory (A+ 0−A+9) share the same memory buffer with M0−M9,
respectively

Publication Release Date: January 1999

- 5 - Revision A1

Preliminary W91F820N SERIES

HFI

HFI

HFI

HFI

HFI

HFI

• EM1, ..., EM3: Emergency one-touch memory key

• F1, ..., F4: Flash function keys: F1 = 600 mS, F2 = 300 mS, F3 = 73 mS, F4 = 100 mS; all flash

pause time is 1.0 mS

Note: D1, ..., Dn, D1`, ..., Dn`, */T, #, Mn: EM1, ..., EM3, Ln: 0−9

Normal Dialing

OFF HOOK (or ON HOOK &

1. D1, D2, …, Dn will be dialed out.

2. Dialing length is unlimited, but redial is inhibited if length oversteps 32 digits in normal dialing.

), D1 , D2

, …,

Dn

Redialing Dialing

OFF HOOK (or ON HOOK &

Come ON HOOK , OFF HOOK (or ON HOOK &

The R/P key can execute redial function only as first key-in after off-hook. Otherwise, it will invoke
the pause function.

, D1 , D2

, …,

Dn , BUSY

), R/P

Number Store

1. OFF HOOK (or ON HOOK &
Mn (or A , Ln or SAVE )

a. The dialing out of D1 to Dn must first be finished before the S key is pressed.
b. D1, D2, …, Dn will be stored in memory location Mn or saved and then dialed out.

2. OFF HOOK (or ON HOOK &

), D1 , D2 , ..., Dn , S , S ,

), S , D1 , D2 , ..., Dn , S ,

Mn (or A , Ln or SAVE )

a. D1, D2, …, Dn will be stored in memory location, Mn (or saved), but will not be dialed out.

b. R/P and */T keys can be stored as a digit in memory, but the R/P key cannot be the

first digit. In store mode, R/P is the pause function key.

c. The store mode is released after the store function is executed or when the state of the hook

switch changes or the flash function is executed.

Save

OFF HOOK (or ON HOOK &

a. D1, D2, ..., Dn will be dialed out.

b. If the dialing of D1 to Dn is finished, pressing SAVE will duplicate D1 to Dn to the

save memory.

), D1 , D2 , ..., Dn , Save

- 6 -