HD66421TB0 HITACHI [Hitachi Semiconductor], HD66421TB0 Datasheet - Page 18

• Manufacturer Part Number: HD66421TB0
• Description: (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)
• Manufacturer: HITACHI [Hitachi Semiconductor]

Word Length
The HD66421 can handle either 8- or 6-bits as a
word. In the display memory, one X address is
assigned to each word of 8- or 6-bits long in X
direction.
H'00
H'01
H'62
H'63
Y0
Y1
Y0
Y1
Preliminary
H'0
H'0
SEG1
1 1 1 0 0 1
0 0 0 1 1 0
D
B
5
1 1 1 0 0 1
0 0 0 1 1 0
D
B
5
MSB
8 bits
D
B
4
D
B
4
H'0
(a) WLS= 1, ADC = 0, MON= 0
H'35's bit7,6, and 3 to 0 are disable .
(c) WLS= 1, ADC = 0, MON= 1
H'34's bit7,6, and 1,0 are disable .
(a) Address assignment when one
word is 8 bits long (MON=0)
D
B
3
D
B
3
D
B
2
D
B
2
D
B
1
D
B
1
H'1
LCD drive signal output
D
B
0
D
B
0
Display RAM
Display RAM
X addresses
Figure 11 Display RAM Addresses in Gray Scale Mode
Figure 12 Display RAM Bits Map at 6-bits Mode
D
B
0
0 0
1 1
D
B
5
D
B
0
D
B
4
1 0 0
0 1 1
1 0 0
0 1 1
D
B
5
D
B
3
H'27
H'35
H'34
SEG160
D
B
4
D
B
2
H'62
H'63
H'00
H'01
18
Y0
Y1
Y0
Y1
When the 6-bits mode is selected, only data on
DB5 to DB0 are used and data on DB7 and
DB6 are discarded. This word length is only
applied to data to internal RAM. The word
length of internal register is always 8-bits
SEG1
H'34
H'35
D
B
1
D
B
0
1 1 1 0 0 1
0 0 0 1 1 0
1 1 1 0 0 1
0 0 0 1 1 0
6 bits
H'0
D
B
0
D
B
1
(b) WLS= 1, ADC = 1 MON= 0
H'0's bit7 to 2 are disable.
(d) WLS= 1, ADC = 1, MON= 1
H'0's bit7 to 4 are disable.
(b) Address assignment when one
word is 6 bits long (MON=0)
D
B
3
D
B
2
MSB
H'1
D
B
2
D
B
3
D
B
5
D
B
4
LCD drive signal output
D
B
4
D
B
5
Display RAM
Display RAM
X addresses
Rev. 1.1E '99.02.10
0 0
1 1
D
B
5
D
B
0
HD66421
H'34
D
B
4
D
B
1
1 0 0
0 1 1
1 0 0
0 1 1
H'0
D
B
1
H'0
D
B
2
SEG160
H'35
D
B
0
D
B
3