Specifications

REV.-A
Power On
CPU Self Reset
$
4
+5 V Line
VCCON
-I
DISC
u
THLD
RESET
Figure 2-20. RESET Signal Timing
2.3.3 Sensor Circuits
Figure 2-21 shows the sensor circuits in block diagram form. Detection of any excessive printhead
temperature causes the TEMP2 signal to be sent directly to the CPU. Other signals, such as the CRHOME
signal, pass through the STK-6022B unit before reaching the CPU. Terminals P50 to P55 on the CPU
are used for the A/D convertor.
The Vref circuit generates the A/D convertor reference voltage Vref.
CPU (IC)
P55
P54
P52
P34
P31
STK-6022B (2A)
CRHOUT + CRHOME
PE20UT f-
PE2
PElOUT +
PEl .
GAPOUT +
GAP
LEVOUT +
LEVER
CRHOME
PE2
PEl
GAP
LEVER
P51
AVPP +
VPP
+35 V Line
P50
TEMP2
4.741 v
Vref -
Vref Circuit
Figure 2-21. Sensor Circuit Block Diagram
2-16