HDSP-253X HP [Agilent(Hewlett-Packard)], HDSP-253X Datasheet - Page 7

• Manufacturer Part Number: HDSP-253X
• Description: Eight Character 5 mm Smart Alphanumeric Display
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Electrical Description
Pin Function
RESET (RST, pin 1)
FLASH (FL, pin 2)
ADDRESS INPUTS
(A
CLOCK SELECT
(CLS, pin 11)
CLOCK INPUT/OUTPUT
(CLK, pin 12)
WRITE (WR, pin 13)
CHIP ENABLE (CE, pin 14)
READ (RD, pin 19)
DATA Bus
(D
GND (SUPPLY) (pin 16)
GND (LOGIC) (pin 18)
V
Thermal Test (pin 17)
DD
0
0
-A
-D
(POWER) (pin 15)
4
7
, pins 3-6, 10)
, pins 20, 21, 25-30)
Description
Reset initializes the display.
FL low indicates an access to the Flash RAM and is unaffected by the
state of address lines A
Each location in memory has a distinct address. Address inputs (A
select a specific location in the Character RAM, the Flash RAM or a
particular row in the UDC (User-Defined Character) RAM. A
used to select which section of memory is accessed. Table 1 shows the
logic levels needed to access each section of memory.
Table 1. Logic Levels to Access Memory
This input is used to select either an internal (CLS = 1) or external (CLS = 0)
clock source.
Outputs the master clock (CLS = 1) or inputs a clock (CLS = 0) for slave
displays.
Data is written into the display when the WR input is low and the
CE input is low.
This input must be at a logic low to read or write data to the display and
must go high between each read and write cycle.
Data is read from the display when the RD input is low and the CE
input is low.
The Data bus is used to read from or write to the display.
This is the analog ground for the LED drivers.
This is the digital ground for internal logic.
This is the positive power supply input.
This pin is used to measure the IC junction temperature.
Do not connect.
FL
0
1
1
1
1
A
X
0
0
1
1
4
A
X
0
1
0
1
3
3
Section of Memory
Flash RAM
UDC Address Register
UDC RAM
Control Word Register
Character RAM
-A
4
.
7
A
Character Address
Don’t Care
Row Address
Don’t Care
Character Address
2
A
1
A
0
3
-A
4
are
0
-A
2
)