4
EPSON
S5U1C88816P MANUAL
(PERIPHERAL CIRCUIT BOARD FOR S1C88816/8F360)
3 PRECAUTIONS
• If OSC1 is used in an oscillation frequency other
than 32.768 kHz, select "USER CLOCK" in the
"OSC1 SYSTEM CLOCK" of the "S5U1C88816P
OPTION" using winfog, and supply an external
clock with the desired frequency to the OSC1
terminal. Or select CR oscillation and adjust its
oscillation frequency using the VR2 control on
the S5U1C88816P. When adjusting the fre-
quency, use the OSC1CR pin on the board for
monitoring the CR oscillation frequency.
• The S5U1C88816P has built-in three types of
OSC3 oscillation circuits, crystal oscillation
circuit (4.9152 MHz), ceramic oscillation circuit
(8 MHz) and CR oscillation circuit (variable
frequency).
• If OSC3 is used in an oscillation frequency other
than 4.9152 MHz (crystal) and 8 MHz (ceramic),
select "USER CLOCK" in the "OSC3 SYSTEM
CLOCK" of the "S5U1C88816P OPTION" using
winfog, and supply an external clock with the
desired frequency to the OSC3 terminal. Or
select CR oscillation and adjust its oscillation
frequency using the VR3 control on the
S5U1C88816P. When adjusting the frequency,
use the OSC3CR pin on the board for monitor-
ing the CR oscillation frequency.
• When using an external clock for OSC1 or
OSC3, adjust the external clock (amplitude: 5 V
±5%, duty: 50% ±10%) and input into the OSC1
or OSC3 terminal with V
SS
as GND.
• In the S5U1C88816P, the oscillation stability
time of the OSC3 is short compared with the
actual IC. You should assure the time from
OSC3 oscillation start to OSC3 system clock
change (min. oscillation stability time required)
according to the actual IC using software.
• The timings such as the oscillation start and
stop times are different from those of the actual
IC because the logic level of S5U1C88816P is
higher than it of actual IC.
• When switching the clock from OSC3 to OSC1,
be sure to switch OSC3 oscillation OFF with
separate instructions. Using a single instruction
to process simultaneously can cause a malfunc-
tion of the CPU.
• Do not turn the OSC3 oscillation circuit ON in
the low power mode.
Do not switch over the operating mode (normal
mode
↔
high speed mode) in the OSC3
oscillation circuit ON status, as this will cause
faulty operation.
<Internal power supply circuit>
On the actual IC, you can change over the
internal power voltage (set by VDC2, VDC1
and VDC0), but in the S5U1C88816P you
cannot change the actual power voltage, simply
by changing VDC2, VDC1 and VDC0.
For this reason, since the S5U1C88816P will
operate, even if the stable time required for
changeover is not taken, you should be sure
that the stable time is provided by the software.
Also, since the usable frequency of OSC1 and
OSC3 depends on the internal power voltage,
you should refer to the Technical Manual for
the S1C88816 or S1C8F360 and take care so as
not to operate it with an inappropriate combi-
nation.
When turning the OSC3 oscillation circuit after
switching the operating voltage, you should
allow a voltage stable waiting time of 5 msec by
the software.
<LCD drive power>
• When the internal LCD power is selected using
winfog, the S5U1C88816P generates the same
LCD drive voltage regardless of the selected
voltage (4.5 V or 5.5 V). However, the selected
voltage level is indicated with the LED.
• When external LCD power is selected using
winfog, the internal LCD power supply circuit
is disconnected and an external power can be
supplied to the V
C1
–V
C5
terminals.
• Since the internal LCD power voltage is lower
than the power supply voltage (5 V), the
display contrast may be lowered if a 5.5 V LCD
panel is used. To check the LCD display in this
case, select external LCD power using winfog
and supply 5 V for the LCD drive voltage.
<Accessing unused addresses>
• When reading or writing to/from an unused
address in the I/O space and ROM/RAM
space, the value is undefined. Be aware that the
undefined value in the S5U1C88816P is differ-
ent from the actual IC.
• When the S5U1C88816P is used with the ICE,
accessing unused addresses can be detected
using the 88816.PAR (for S1C88816) or
88F360.PAR (for S1C8F360) file.
