Lcd Controller/Driver Display Ram; Fig. 14.11 Correspondence Between Display Ram And Common/Segment Output Pins - Fujitsu MB90420/5 (A) Series Hardware Manual

MB90420/5 (A) SERIES F

14.5 LCD Controller/Driver Display RAM

The display RAM is "16 × 8-bit" display data memory for generating segment output signals.
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Display RAM and output pins
Data in this RAM is read automatically in synchronization with timing for selecting the common signal, and
output from the segment output pin.
When the value of each bit is 1, it is converted to the selection voltage (LCD displayed) and then output.
When the value of each bit is 0, it is converted to a non-selection voltage (LCD not displayed) and then
output.
Since the LCD display operation is performed irrespective of the CPU operation, the display RAM can be
read from/written to at any timing.
The pins of the SEG00 to SEG23 pins that are not specified as segment output pins for the LCRH register
can be used as general-purpose ports. Moreover, RAM corresponding to those common output pins can be
used as normal RAM.
Tables 14-5 and 14-6 show the relationship between the duty, common output, and display RAM.
Figure 14.11 shows the correspondence between display RAM and common/segment output pins.
Address
3960
H
bit 11
3961
H
bit 15
3962
H
bit 11
3963
H
bit 15
3964
H
bit 11
3965
H
bit 15
3966
H
bit 11
3967
H
bit 15
3968
H
bit 11
3969
H
bit 15
396A
H
bit 11
396B
H
bit 15
COM3

Fig. 14.11 Correspondence between Display RAM and Common/Segment Output Pins

2
MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
bit 3 bit 2
bit 7 bit 6
bit 10
bit 14
COM2
bit 1
bit 5
bit 9
bit 13
bit 1
bit 5
bit 9
bit 13
bit 1
bit 5
bit 9
bit 13
bit 1
bit 5
bit 9
bit 13
bit 1
bit 5
bit 9
bit 13
bit 1
bit 5
bit 9
bit 13
COM1
14-16
bit 0 SEG00
bit 4 SEG01
bit 8 SEG02
bit 12 SEG03
bit 0 SEG04
bit 4 SEG05
bit 8 SEG06
bit 12 SEG07
bit 0 SEG08
bit 4 SEG09
bit 8 SEG10
bit 12 SEG11
bit 0 SEG12
bit 4 SEG13
bit 8 SEG14
bit 12 SEG15
bit 0 SEG16
bit 4 SEG17
bit 8 SEG18
bit 12 SEG19
bit 0 SEG20
bit 4 SEG21
bit 8 SEG22
bit 12 SEG23
COM0