CHAPTER 15 VFD CONTROLLER/DRIVER
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User’s Manual U11302EJ4V0UM
15.6 Display Data Memory
The display data memory is the area for storing the segment data to be displayed.
This memory is mapped at addresses FA30H to FA7FH. To display data on the VFD, the VFD controller reads
the data stored in this memory regardless of the type of operations performed by the CPU (DMA operations).
The area not used for the display data can be used as normal RAM area.
At the key scan timing (T
KS
), all segment outputs and digit outputs become “0” and the output latch data of ports
8, 9, 10, 11, and 12 are output to FIP37/P110 to FIP52/P127.
Figure 15-10. Relationship Between Display Data Memory Contents and Segment Output
Bit 7
0 7
0 7
0 7
0 7
0
Display
data
memory
Timing
output
S39
S32 S31
S24 S23
S16 S15
S8 S7
S0
FA70H
FA71H
FA72H
FA73H
FA74H
FA75H
FA76H
FA77H
FA78H
FA79H
FA7AH
FA7BH
FA7CH
FA7DH
FA7EH
FA7FH
FA60H
FA61H
FA62H
FA63H
FA64H
FA65H
FA66H
FA67H
FA68H
FA69H
FA6AH
FA6BH
FA6CH
FA6DH
FA6EH
FA6FH
FA50H
FA51H
FA52H
FA53H
FA54H
FA55H
FA56H
FA57H
FA58H
FA59H
FA5AH
FA5BH
FA5CH
FA5DH
FA5EH
FA5FH
FA40H
FA41H
FA42H
FA43H
FA44H
FA45H
FA46H
FA47H
FA48H
FA49H
FA4AH
FA4BH
FA4CH
FA4DH
FA4EH
FA4FH
FA30H
FA31H
FA32H
FA33H
FA34H
FA35H
FA36H
FA37H
FA38H
FA39H
FA3AH
FA3BH
FA3CH
FA3DH
FA3EH
FA3FH
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
T12
T13
T14
T15
T
KS
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Содержание mPD780204
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