Service manual

R-1855A

31 XOUT OUT Internal clock oscillation frequency control output.

Output to control oscillation input of XIN.

32 VSS IN Power source voltage:-5V.

VC voltage of power source circuit input.

33 P27 IN Signal coming from touch key.

When any one of G12 line keys on key matrix is touched, a corresponding signal will

be input into P27. When no key is touched, the signal is held at "L" level.

34 P26 IN Signal similar to AN1.

When any one of G11 line keys on key matrix is touched, a corresponding signal will

be input into P26.

35 P25 IN Signal similar to P27.

When any one of G10 line keys on key matrix is touched, a corresponding signal will

be input into P25.

36 P24 IN Signal similar to P27.

When any one of G9 line keys on key matrix is touched, a corresponding signal will be

input into P24.

37-40 P23-P20 OUT Digit selection signal.

The relationship between digit signal and digit are as

follows;

Digit signal Digit Digit signal Digit

P14 ........................... 1st. P20 .......................... 5th.

P15 .......................... 2nd. P21 .......................... 6th.

P16 .......................... 3rd. P22 .......................... 7th.

P17 ........................... 4th. P23 .......................... 8th.

(ß : INTO signal)

Refer to the touch control panel circuit about the rela-

tion between signals and digits. Normally, one pulse is

output in every synchronized signal (ß) period, and

input to the grid of the fluorescent display.

41-44 P17-P14 OUT Digit selection signal. Signal similar to P23.

45-48 P13-P10 OUT Segment data signal. Signal similar to P55.

49 P07 OUT Segment data signal. Signal similar to P55.

50 P06 OUT Segment data signal. Signal similar to P55.

Key strobe signal.