Philips Semiconductors
34 × 128 pixel matrix driver
Product specification
PCF8531
8.16 LCD waveforms and DDRAM to data mapping
The LCD waveforms and the DDRAM to display data mapping are shown in Figs 2, 3 and 4.
ROW 0
R0 (t)
VLCD
V2
V3
V4
V5
VSS
ROW 2
R2 (t)
VLCD
V2
V3
V4
V5
VSS
COL 0
C0 (t)
VLCD
V2
V3
V4
V5
VSS
COL 1
C1 (t)
VLCD
V2
V3
V4
V5
VSS
VLCD
V3 − VSS
VLCD − V2
Vstate1(t) 0 V
V3 − V2
VLCD
V3 − VSS
VLCD − V2
Vstate2(t) 0 V
V3 − V2
Vstate1(t) = C1(t) − R0(t).
Vstate2(t) = C1(t) − R2(t).
0 2 4 6 8...
frame n
frame n + 1
... 32 1 3 5 7...
... 33 0 2 4 6 8...
... 32 1 3 5 7...
Fig.2 Typical LCD driver waveforms.
Vstate1(t)
Vstate2 (t)
V4 − V5
0V
VSS − V5
V4 − VLCD
−VLCD
V4 − V5
0V
VSS − V5
V4 − VLCD
−VLCD
... 33
MGS466
2000 Feb 11
8