HT16270
Pad Description
Pad No.
1
2
3
4
5
6
7
8, 9
10~13
14~29
30~93
Pad Name
DATA
VSS
OSCI
OSCO
VDD
VLCD
IRQ
BZ, BZ
T1~T4
COM0~COM15
SEG0~SEG63
I/O
¾
I
O
¾
I
O
O
I
O
O
Description
Negative power supply, ground
Crystal oscillator input pin
Crystal oscillato output pin
Positive power supply
LCD operating voltage input pad.
Time base or watchdog timer overflow flag, NMOS open drain
output
2kHz or 4kHz tone frequency output pair (Tristate output
buffer)
Not connected
LCD common outputs
LCD segment outputs
Chip selection input with pull-high resistor. When the CS is
logic high, the data and command read from or write to the
HT16270 are disabled. The serial interface circuit is also reset.
But if the CS is at logic low level and is input to the CS pad, the
data and command transmission between the host controller
and the HT16270 are all enabled.
READ clock input with pull-high resistor. Data in the RAM of
the HT16270 are clocked out on the rising edge of the RD sig-
nal. The clocked out data will appear on the data line. The host
controller can use the next falling edge to latch the clocked out
data.
WRITE clock input with pull-high resistor. Data on the DATA
line are latched into the HT16270 on the rising edge of the WR
signal.
I/O Serial data input/output with pull-high resistor
94
CS
I
95
RD
I
96
WR
I
Absolute Maximum Ratings
Supply Voltage .............................-0.3V to 5.5V
Input Voltage .................V
SS
-0.3V
to V
DD
+0.3V
Storage Temperature.................-50°C to 125°C
Operating Temperature ..............-25°C to 75°C
Note: These are stress ratings only. Stresses exceeding the range specified under
²Absolute
Maxi-
mum Ratings² may cause substantial damage to the device. Functional operation of this device
at other conditions beyond those listed in the specification is not implied and prolonged expo-
sure to extreme conditions may affect device reliability.
5
April 21, 2000
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
