HDLA-2416 datasheet(11/18 Pages) BOARDCOM

11 / 18 page

Broadcom

- 11 -

HDLx-2416 Series

Data Sheet

Display Internal Block Diagram

Figure 1 shows the HDLX-2416 display internal block diagram.

The CMOS IC consists of a 4×7 Character RAM, a 2×4 Attribute

RAM, a 5-bit Control Register, a 128 character ASCII decoder

and the refresh circuitry necessary to synchronize the decoding

and driving of four 5×7 dot matrix displays.

Four 7-bit ASCII words are stored in the Character RAM. The IC

reads the ASCII data and decodes it via the 128 character ASCII

decoder. The ASCII decoder includes the 64 character set of the

HPDL-2416, 32 lower case ASCII symbols, and 32 foreign

language symbols.

A 5-bit word is stored in the Control Register. Three fields

within the Control Register provide an 8-level brightness

control, master blank, and extended functions disable.

For each display digit location, two bits are stored in the

Attribute RAM. One bit is used to enable a cursor character at

each digit location. A second bit is used to individually disable

the blanking features at each digit location.

The display is blanked and dimmed through an internal

blanking input on the row drivers. Logic within the IC allows

the user to dim the display either through the BL input or

through the brightness control in the control register. Similarly

the display can be blanked through the BL input, the Master

Blank in the Control Register, or the Digit Blank Disable in the

Attribute RAM.

HDLA-2416 Datasheet(PDF) 11 Page - Broadcom Corporation.