m3819 Renesas Electronics Corporation., m3819 Datasheet - Page 142

• Manufacturer Part Number: m3819
• Description: Mitsubishi 8-bit Single-chip Microcomputer 740 Family / 38000 Series
• Manufacturer: Renesas Electronics Corporation.

2. APPLICATION
Fig. 2.5.25 Control procedure of Digit key-scan
128
Digit key-scan (FLD digit interrupt) :
Push register to stack etc.
FLD digit interrupt processing routine
Store the contents of Work RAM
into buffer
Transfer the contents of P2
(Address:04
Wait for Key-scan
16
~ ~
RTI
) to Work RAM
3819 Group USER’S MANUAL
Digit key-scan
Wait until the digit output is stabilized since
the digit output waveform may dull because of
the printed circuit board (PCB) pattern wiring
length or other factors.
Read keys.
(Set the Port P2 direction register (P2D)
(Address:05
initialization.)
16
) to the input mode in the
2.5 FLD controller
MITSUBISHI MICROCOMPUTER
3819 Group