Data Sheet
Table Of Contents
- Overview
- Features
- Applications
- Device Selection Guide
- Package Dimensions
- Absolute Maximum Ratings
- ASCII Character Set
- Recommended Operating Conditions
- Electrical Characteristics
- Optical Characteristics
- AC Timing Characteristics
- AC Timing Frequency Characteristics
- Electrical Description
- Display Internal Block Diagram
- Character RAM
- UDC RAM and UDC Address Register
- Flash RAM
- Control Word Register
- Brightness (Bits 0–2)
- Flash Function (Bit 3)
- Blink Function (Bit 4)
- Current Requirements at Different Brightness Levels (VDD = 5.0V)
- Self-Test Function (Bits 5, 6)
- Clear Function (Bit 7)
- Display Reset
- Mechanical and Electrical Considerations
- Thermal Considerations
- Ground Connections
- Thermal Resistance (θJA) Using Various Amounts of Heatsinking Material
- Soldering and Post Solder Cleaning Instructions for the HDSP-210X/- 211X/250X
- Contrast Enhancement
- Intensity Bin Limits for HDSP-2107
- Intensity Bin Limits for HDSP-211x and HDSP-250x (Except HDSP-2504)
- Intensity Bin Limit for HDSP-2504
- Color Bin Limits
- Packing Information
Broadcom AV02-0629EN
13
HDSP-210x/-211x/-250x Series Data Sheet Eight-Character 5 mm and 7 mm Smart Alphanumeric Displays
Figure 9: Data to Load F to the UDC RAM
Flash RAM
Figure 10 shows the logic levels required to access the Flash RAM. The Flash RAM has one bit associated with each
location of the Character RAM. The Flash input is used to select the Flash RAM while address lines A
3
–A
4
are ignored.
Address lines A
0
–A
2
are used to select the location in the Flash RAM to store the attribute. D
0
is used to store or remove
the flash attribute. D
0
= 1 stores the attribute and D
0
= 0 removes the attribute.
When the attribute is enabled through bit 3 of the Control Word and a 1 is stored in the Flash RAM, the corresponding
character flashes at approximately 2 Hz. The actual rate is dependent on the clock frequency. For an external clock the flash
rate can be calculated by dividing the clock frequency by 28,672.
Control Word Register
Figure 11 shows how to access the Control Word Register. This 8-bit register performs five functions: Brightness control,
Flash RAM control, Blinking, Self Test, and Clear. Each function is independent of the others; however, all bits are updated
during each Control Word write cycle.
Brightness (Bits 0–2)
Bits 0–2 of the Control Word adjust the brightness of the display. Bits 0–2 are interpreted as a three bit binary code with code
(000) corresponding to maximum brightness and code (111) corresponding to a blanked display. In addition to varying the
display brightness, bits 0–2 also vary the average value of I
DD
. I
DD
can be calculated at any brightness level by multiplying
the percent brightness level by the value of IDD at the 100% brightness level. These values of I
DD
are shown in Current
Requirements at Different Brightness Levels (V
DD
= 5.0V).
Flash Function (Bit 3)
Bit 3 determines whether the flashing character attribute is on or off. When bit 3 is a 1, the output of the Flash RAM is
checked. If the content of a location in the Flash RAM is a 1, the associated digit flashes at approximately 2 Hz. For an
external clock, the blink rate can be calculated by driving the clock frequency by 28,672. If the flash enable bit of the Control
Word is a 0, the content of the Flash RAM is ignored. To use this function with multiple display systems, see the Display
Reset section.
C
O
L
1
D
4
D
3
D
2
D
1
D
0
UDC Character Hex Code
1 1 1 1 1 Row 1 • • • • • 1F
1 0 0 0 0 Row 2 • 10
1 0 0 0 0 Row 3 • 10
1 1 1 1 0 Row 4 • • • • 1D
1 0 0 0 0 Row 5 • 10
1 0 0 0 0 Row 6 • 10
1 0 0 0 0 Row 7 • 10
Ignored
C
O
L
2
C
O
L
3
C
O
L
4
C
O
L
5
0 = Logic 0; 1 = Logic 1; * = Illuminated LED