1997 Dec 16

13

Philips Semiconductors

Product specification

LCD controller/driver

PCF2104x

Fig.8 Relationship between CGRAM addresses, data and display patterns.

handbook, full pagewidth

MGA800 - 1

7

654

321

0

654

321

0

432

10

higher

order

bits

lower

order

bits

lower

order

bits

higher

order

bits

lower

order

bits

higher

order

bits

0

000

000

0

0

000

000

0

001

00

0

010

00

0

011

0

100

0

0

0

101

00

0

110

00

0

111

000

00

000

00

0

001

0

0

0

010

00

00

011

100

101

00

00

110

00

00

111

000

00

001

0

000

000

1

0

001

0

000

001

0

0

000

111

1

0

000

111

1

0

000

111

1

0

000

111

1

01

0

0

000

100

101

110

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

11

1

character codes

(DDRAM data)

CGRAM

address

character patterns

(CGRAM data)

character

pattern

example 1

cursor

position

character

pattern

example 2

Character code bits 0 to 3 correspond to CGRAM address bits 3 to 6.

Character pattern column positions correspond to CGRAM data bits 0 to 4; bit 4 being at the left end, as shown in the figure.

CGRAM character patterns are selected when character code bits 4 to 7 are all logic 0. CGRAM data = logic 1 corresponds to selection for display.

Only bits 0 to 5 of the CGRAM address are set by the ‘Set CGRAM address’ instruction. Bit 6 can be set using the ‘Set DDRAM address’ instruction or

by using the auto-increment feature during CGRAM write. All bits 0 to 6 can be read using the ‘Read Busy Flag and address’ instruction.