pca85162 NXP Semiconductors, pca85162 Datasheet - Page 14

• Manufacturer Part Number: pca85162
• Description: Universal Lcd Driver For Low Multiplex Rates
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA85162_1
Product data sheet
7.10 Display RAM
The display RAM is a static 32 × 4-bit RAM which stores LCD data.
There is a one-to-one correspondence between
A logic 1 in the RAM bitmap indicates the on-state of the corresponding LCD element;
similarly, a logic 0 indicates the off-state.
The display RAM bit map,
backplane outputs BP0 to BP3, and the columns 0 to 31 which correspond with the
segment outputs S0 to S31. In multiplexed LCD applications the segment data of the first,
second, third, and fourth row of the display RAM are time-multiplexed with BP0, BP1,
BP2, and BP3 respectively.
When display data is transmitted to the PCA85162, the display bytes received are stored
in the display RAM in accordance with the selected LCD drive mode. The data is stored as
it arrives and does not wait for an acknowledge cycle as with the commands. Depending
on the current multiplex drive mode, data is stored singularly, in pairs, triples or
quadruples. To illustrate the filling order, an example of a 7-segment numeric display
showing all drive modes is given in
applies equally to other LCD types.
Fig 9.
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In static drive mode the same signal is carried by all four backplane outputs and they
can be connected in parallel for very high drive requirements.
the bits in the RAM bitmap and the LCD elements
the RAM columns and the segment outputs
the RAM rows and the backplane outputs.
display RAM rows/
backplane outputs
The display RAM bitmap shows the direct relationship between the display RAM column and the
segment outputs; and between the bits in a RAM row and the backplane outputs.
Display RAM bit map
rows
(BP)
All information provided in this document is subject to legal disclaimers.
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Rev. 01 — 19 April 2010
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Figure
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9, shows the rows 0 to 3 which correspond with the
Figure
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display RAM addresses/segment outputs (S)
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Universal LCD driver for low multiplex rates
10; the RAM filling organization depicted
columns
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PCA85162
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© NXP B.V. 2010. All rights reserved.
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