CHAPTER 3: PRECAUTIONS ON USING THE S5U1C63004P PERIPHERAL CIRCUIT BOARD
S5U1C63004P MANUAL (PERIPHERAL CIRCUIT
EPSON
5
BOARD FOR S1C63454/63455/63458/63466)
<SVD circuit>
- Some models have a built-in SVD circuit that detects the voltage supplied from outside the terminal,
but this board cannot directly detect the supply voltage. The SVD function is evaluated by artificially
changing the power-supply voltage using the VSVD control on the S5U1C63004P board.
- There is a delay between the time the power to the SVD circuit is turned on and the time the SVD data
is detected. This delay on the S5U1C63004P board is set to between 61 and 92
µ
sec. For the delay on an
actual IC, consult the technical hardware manual to ensure that there is a sufficient delay before the
output voltage is detected.
<Oscillator circuit>
- There must be a waiting period between the time the OSC3 oscillation control circuit (OSCC) is turned
on and the moment at which oscillation stabilizes. The oscillator on the S5U1C63004P board can
operate when it is switched to OSC3 without the insertion of a waiting period. Therefore, consult the
technical hardware manual to set an appropriate waiting period on the actual IC.
- Separate instructions should be used to switch the clock from OSC3 to OSC1, and to stop the OSC3
circuit from oscillating. If these operations are performed simultaneously by one instruction, care
should be exercised. Although such operations are performed normally on the S5U1C63004P board,
an actual IC may not perform correctly.
- When using an external clock, make sure that it is adjusted for an amplitude of 5 V
±
5% and for a
duty cycle of within 50%
±
10%, and that it is input from the I/O connectors OSC1 and OSC3 with V
SS
set for GND.
- Since the logic level on the S5U1C63004P board is high, its oscillation starting and oscillation stopping
times are different from those of an actual IC.
- The S5U1C63004P board contains oscillators for the OSC1 and OSC3. If the OSC3 oscillator is not used
on an actual IC, care should be exercised because operations are performed on the emulation board by
using its OSC3 circuit.
<Access to undefined address space>
If undefined address space in the ROM or RAM is accessed for read or write, the read or written
values become indeterminate. Furthermore, since the way these values become indeterminate is
different in the S5U1C63004P board and an in actual IC, care should be exercised. Note that the ICE
has a function to cause program execution to break when access to an undefined address space is
attempted.
<Reset circuit>
- The S5U1C63004P board does not contain an oscillation stop detection circuit (to generate a system
reset signal when the oscillation has stopped). Note that the oscillation stop detection circuit does not
guarantee operation with 100% accuracy.
- The sequence of operations from when the ICE is powered on until the program starts operating is
different in the S5U1C63004P board and an actual IC. The ICE enters a ready state when the user
program, etc., as well as option data are loaded on the S5U1C63004P board.
<Internal power supply circuit>
- For VDC, DBON, HLON, VDSEL, and VCSEL, the S5U1C63004P board only contains registers and
does not actually control the voltages. Therefore, consult the technical hardware manual to set the
exact voltages. Furthermore, if the operating voltage (e.g., VDC) is switched over, consult the techni-
cal hardware manual to set a waiting period for stabilization.
- Although the S5U1C63004P board has a control (VLCD) to adjust the LCD drive voltage, an actual IC
in almost all cases does not have such an adjustment facility; therefore, be careful. Note that this
control is useful for only those models whose LCD drive bias is 1/2 or 1/3.
- The operating frequency range that can be used depends on the internal power-supply voltage.
Therefore, consult the technical hardware manual to ensure that your system will not be operated
with an improper combination of operating frequency and internal power-supply voltage.
