ESC1621

p. 4

Last update: 2004-03-05 12:13

Pad Description

Pad No.

Pad Name

I/O

Function

1

CS

I

Chip selection input with pull-high resistor

When the CS is logic high, the data and command read from or written

to the ESC1621 are disabled. The serial interface circuit is also reset. But

if CS is at logic low level and is input to the CS pad, the data and com-

mand transmission between the host controller and the ESC1621 are all

enabled.

2

RD

I

READ clock input with pull-high resistor

Data in the RAM of the ESC1621 are clocked out on the falling edge of

the RD signal. The clocked out data will appear on the DATA line. The

host controller can use the next rising edge to latch the clocked out data.

3

WR

I

WRITE clock input with pull-high resistor

Data on the DATA line are latched into the ESC1621 on the rising edge

of the WR signal.

4

DATA

I/O

Serial data input/output with pull-high resistor

5

GND

—

Negative power supply, ground

6

OSCO

O

7

OSCI

I

The OSCI and OSCO pads are connected to a 32.768kHz crystal in order

to generate a system clock. If the system clock comes from an external

clock source, the external clock source should be connected to the OSCI

pad. But if and on-chip RC oscillator is selected instead, the OSCI and

OSCO pads can be left open.

8

VLCD

I

LCD power input

9

VDD

—

Positive power supply

10

IRQ

O

Time base or WDT overflow flag, NMOS open drain output

11,12

BZ, BZ

O

2kHz or 4kHz tone frequency output pair

13~16

COM0~COM3

O

LCD common outputs

48~17

SEG0~SEG31

O

LCD segment outputs

Absolute Maximum Ratings

Supply Voltage…………...…..… -0.3V ~ 5.5V

Storage Temperature…………… -50

Operating Temperature………….. -25

Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute Maxi-

mum Ratings”may cause substantial damage to the device. Functional operation of this de-

vice at other conditions beyond those listed in the specification is not implied and prolonged

exposure to extreme conditions may affect device reliability.