HPDL-1414 Datasheet, PDF (10/12 Pages) Agilent(Hewlett-Packard) – Four Character Smart Alphanumeric Displays

ensure that the correct data is
stored in the display. If D₀ is in a
low state during the write cycle,
then a cursor character will be
removed at the indicated
location. If D₀ is in a high state
during the write cycle, then a
cursor character will be stored at
the indicated location. The
presence or absence of a cursor
character does not affect the
ASCII data stored at that location.
Again, when A₁ = A₀ = 0, the
cursor character is stored in the
furthest right-hand display
location.
All stored cursor characters are
displayed if the cursor enable
(CUE) is high. Similarly, the
stored ASCII data words are
displayed, regardless of the
cursor characters, if the cursor
enable (CUE) is low. The cursor
enable (CUE) has no effect on the
storage or removal of the cursor
characters within the display. A
flashing cursor is displayed by
pulsing the cursor enable (CUE).
For applications not requiring a
cursor, the cursor enable (CUE)
can be connected to ground and
the cursor select (CU) can be
connected to V_CC. This inhibits
the cursor function and allows
only ASCII data to be loaded into
the display.
Display Clear HPDL-2416
As shown in Figure 4, the ASCII
data stored in the display will be
cleared if the clear (CLR) is held
low and the blanking input (BL)
is held high for 4 ms minimum.
The cursor memory is not
affected by the clear (CLR) input.
Cursor characters can be stored
or removed even while the clear
(CLR) is low. Note that the
display will be cleared regardless
of the state of the chip enables
(CE₁, CE₂). However, to ensure
that all four display characters
are cleared, CLR should be held
low for 4 ms following the last
write cycle.
Function BL CLR CUE CU CE₁ CE₂ WR A₁ A₀ D₆ D₅ D₄ D₃ D₂ D₁ D₀ DIG₃ DIG₂ DIG₁ DIG₀
Write
L X X H L L L L L a a a a a a a NC NC NC
Data
-OR-
L H b b b b b b b NC NC
NC
Memory X H X H L L L H L c c c c c c c NC
NC NC
HH d d d d d d d
NC NC NC
Disable
X X X H X X H XX XXX X X XX
Data
XX XHX H X
Memory X X X H H X X
Write
Previously Written
Data
Write
Cursor
X X X L L L L L L X X X X X X H NC NC NC
L H X X X X X X H NC NC
NC
H L X X X X X X H NC
NC NC
HH XXX X X XH
NC NC NC
Clear
Cursor
X X X L L L L L L X X X X X X L NC NC NC
L H X X X X X X L NC NC
NC
H L X X X X X X L NC
NC NC
HH XXX X X X L
NC NC NC
Disable
Cursor
Memory
X X X L X X H XX XXX X X XX
XX XLX H X
XX XLH X X
Previously Written
Cursor
L = LOGIC LOW INPUT
H = LOGIC HIGH INPUT
X = DON’T CARE
“a” = ASCII CODE CORRESPODING TO SYMBOL “ ”
NC = NO CHANGE
= CURSOR CHARACTER (ALL SEGMENTS ON)
Figure 4a. Cursor/Data Memory Write Truth Table.
Function
CUE
Clear
Blanking
BL CLR CUE CU CE₁ CE₂ WR DIG₃ DIG₂
HH
LXXXX
HH
HXXXX
HL
X X X X X_*
*NOTE: CLR should be held low for 4 ms
following the last WRITE cycle to ensure
all data is cleared.
LX
XXXXX
DIG₁
DIG₀
Figure 4b. Displayed Data Truth Table.
Display previously written data
Display previously written cursor
Clear data memory, cursor memory
unchanged
Blank display, data and cursor"
memories unchanged.
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