Philips Semiconductors
(67 + 1) × 102 pixels matrix LCD driver
Product speciï¬cation
PCF8813
11.10 Free programmable multiplex rate
The free programmable multiplex rate concept allows the
user to limit the number of rows selected to groups of eight.
Any, or all of these groups of rows can be enabled or
disabled. The mask register command (M[7:0]) allows the
user to turn-on or turn-off blocks of eight rows.
Each mask value controls a block of eight rows, thus in
partial mode the maximum number of rows available is
64 plus the icon row. A logic 1 in the mask register enables
the rows available within that block of rows, and a logic 0
disables them.
The mask register causes the row counter to count eight
bits and then jump to the next enabled 8-bit group. For
example, if the mask register value is 00001101, then the
rows available will be 0 to 7, 16 to 23, 24 to 31 and 67.
Rows 8 to 15 and 32 to 63 have been skipped. This
information is also mapped to the RAM so that only the
contents of active rows are displayed.
Table 13 Range of free programmable multiplex rates
MASK REGISTER
M0
M1
M2
M3
M4
M5
M6
M7
ROWS AVAILABLE
R0 to R7 + icon row
R8 to R15 + icon row
R16 to R23 + icon row
R24 to R31 + icon row
R32 to R39 + icon row
R40 to R47 + icon row
R48 to R55 + icon row
R56 to R63 + icon row
Table 14 Examples of display normal driving mode and partial display driving mode
MASK REGISTER
MASK VALUE
ROW SEQUENCE
N/P = 1 (the mask value is don’t care when N/P = 1 because all rows are enabled)
M0
1
0 to 7
M1
0
8 to 15
M2
0
16 to 23
M3
1
24 to 31
M4
0
32 to 39
M5
0
40 to 47
M6
0
48 to 55
M7
1
56 to 63
not available in mask register
64 to 66
not available in mask register
67 (icon row)
N/P = 0
M0
1
0 to 7
M1
0
8 to 15
M2
0
16 to 23
M3
1
24 to 31
M4
0
32 to 39
M5
0
40 to 47
M6
0
48 to 55
M7
1
56 to 63
not available in mask register
67 (icon row)
NORMAL DISPLAY
battery status: XXX
address book
connection time
network: YYY
reception strength
2 June; 15:25
keyboard locked
battery status: XXX
network: YYY
keyboard locked
2004 Mar 05
33