Philips D2999 - Page 7

TIE PB2 (CONNECTOR 1/2} TO MASS
PB2=0
N
NORMAL FUNCTIONING
IF NOT: uP IS OEFECTIVE
3 101 404
| OUTPUT 1010 TO PB.D.E.F.G PORTS —
SEE TABLE 2
PB2=0.
PB2= OPEN N
OUTPUT 0101 TO 0.£.6 PORTS
SEE TABLE 2
N OUTPUT 1001 TO D PORT
SEE TABLE 2
Y
ALL LEDS ON
Ie
Y
PB2 TO MASS
OUTPUT 0101 TO PA.PB
Fig. 4
35 844012
1/0 Port
PAo
PAY
PAg
PAZ
PBo
PB
PB2
PB3
Do
Dy
Do
D3
Eo
ey
Ee
E3
Fo
F4
Fo
F3
Go
G1
G2
G3
Pin
PON —
uP2 TABLE 2
Conn. 1/2 Conn.1/2 conn. 1/2
PBo = 0 PB2 = cpen PB2 =0
+5 0° 0
0 0. +5"
0 0 0,
0 +5" . +5""
+5* +5* 0*
0 8) +5,
0 +5 0:
0 07 +5)
+5 0 0. Display:
0 +5 +5 | Alt LEDs on***
+5 0 |
0 +5 +5 |
+5 0 0!
oO 45 +5.
+5 0 0:
0 +5 +5
+5 0 O°
0 0 0:
+5 0 0:
0 J +5*** +5*0**
+5 Q 0:
0 +5 45 -
+5 0 0
0 +5 +5
*In some set versions this pin hag been connected to mass.
** Wide/Narrow switch to Wide,
*** Signal consists of pulses.
“*** Supply voltage with pulses.
“= When there is no display:
09,1,2,3 = +5, 0, 0, +5 — RAM of second uP is defective
Do,1,2,3 = 9, +5, 0, +5 — LED or driver is defective
1/0 Port
PAg
PAy
PA
PA3
PBo
_ PB
PBo
PB3
Gg
* Can ont
to +3.
™ This pin
“* When th