CHAPTER 3: PRECAUTIONS ON USING THE S5U1C63004P PERIPHERAL CIRCUIT BOARD
4
EPSON
S5U1C63004P MANUAL (PERIPHERAL CIRCUIT
BOARD FOR S1C63454/63455/63458/63466)
- Those that can be estimated by checking LEDs and monitor pins
a) Run and Halt execution ratio (check the LED on the ICE)
b) CPU operating voltage switching circuit (VDC)
c) OSC3 oscillation ON/OFF circuit (OSCC)
d) CPU clock switching circuit (CLKCHG)
e) Voltage doubler ON/OFF circuit (DBON)
f) Voltage halver ON/OFF circuit (HLON)
g) Oscillation system voltage regulator power supply select circuit (VDSEL)
h) LCD system voltage regulator power supply select circuit (VCSEL)
i) SVD ON/OFF circuit (SVDON)
j) LCD power supply ON/OFF circuit (LPWR)
k) LCD constant-voltage switching circuit (VCCHG)
- Those that require attention during system and software design
l) Currents consumed by internal pull-up resistors
m) Input ports in a floating state
(3) Functional difference
<LCD power supply circuit>
There is a delay between the time the LCD power supply circuit (LPWR) is turned on and the time the
LCD drive waveform is output. This delay on the S5U1C63004P board is set to 107 msec. The delay on
an actual IC is different, however. Consult the technical hardware manual.
(When 1/5 bias [V
SS
, V
C1
, V
C2
, V
C3
, V
C4
, V
C5
] selected)
In the actual IC, the SEG and COM terminals are fixed at V
SS
level when the LPWR register is set
to "0" (the LCD power control circuit goes off) in external power mode. However, in this board and
the LCD board, the COM terminals go to V
C1
level and the SEG terminals go to V
SS
level.
(When 1/2 or 1/3 bias [V
SS
, V
C1
, V
C2
, V
C3
] selected)
Turning the LPWR register off in the external power mode stops outputting the LCD drive wave-
form. At this time, the output voltage of this board is different from the actual IC as shown below.
1/2 bias
1/3 bias
SEG terminal
COM terminal
Actual IC
V
SS
V
C1
–V
C2
S5U1C63004P
V
C3
V
C1
–V
C2
SEG terminal
COM terminal
Actual IC
V
C1
V
C1
S5U1C63004P
V
C2
V
C1
<LCD drive waveform>
Pay attention when using this board for the model that can control static drive waveform output,
because the output waveform is different from the actual IC. (Only for 1/3 bias with V
SS
, V
C1
, V
C2
, V
C3
.)
V
C3
V
C2
V
C1
V
SS
V
C3
V
C2
V
C1
V
SS
V
C3
V
C2
V
C1
V
SS
V
C3
V
C2
V
C1
V
SS
<Actual IC>
<This board, LCD board>
SEG
terminal
COM
terminal
SEG
terminal
COM
terminal
Segment
register
1
0
