Epson EPL-N1200, Service Manual

Page: 79 / 149

2.2.1.1 Reset Circuit
The entire system (CPU and external devices) can be initialized if the RESET signal (CPU pin 113)
is active simultaneously. This circuit uses an M5193B IC to monitor the supply voltage if the voltage
level less than 4.25 V is detected. The reset time is approximately 128 ms.
2.2.1.2 Bus Control Circuit
The MB86930 CPU outputs the R/W (read/write) signal, AS (address strobe) signal, and the BE0,
BE1, BE2, and BE3 signals (byte enables) to the ASIC E05A91. The ASIC E05A91 uses these
signals to generate the RD (read strobe) signal, WR (write strobe) signal, and READY signal.
+5V
Vcc
C
OUT
+5V
M51953B
(IC2)
RESET RSTOUT RSTIN
E05B31
(IC38)
Figure 2-29. Reset Circuit
R/W
AS
BE0-3
RD WR
READY
Data
Bus Address
Bus
CPU
MB86930
(IC15)
E05A91
(IC1)
Figure 2-30. Bus Control Circuit
Operating Principles EPL-N1200 Service Manual
2-20 Rev. A