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EPSON
S1C63358 TECHNICAL MANUAL
APPENDIX S5U1C63000P MANUAL (PERIPHERAL CIRCUIT BOARD FOR S1C63158/358/P366)
<Access to undefined address space>
If any undefined space in the S1C63158/358/P366's internal ROM/RAM or I/O is accessed for data
read or write operations, the read/written value is indeterminate. Additionally, it is important to
remain aware that indeterminate state differs between this board and the actual IC. Note that the ICE
(S5U1C63000H1/S5U1C63000H2) incorporates the program break function caused by accessing to an
undefined address space.
<Reset circuit>
Keep in mind that the operation sequence from when the ICE and this board are powered on until the
time at which the program starts running differs from the sequence from when the actual IC is
powered on till the program starts running. This is because this board becomes capable of operating
as a debugging system after the user program and optional data are downloaded. When operating the
ICE after placing it in free-running mode, always apply a system reset. A system reset can be per-
formed by pressing the reset switch on this board, by a reset pin input, or by holding the input ports
low simultaneously.
<Internal power supply circuit>
- Although this board contains VDC, DBON, HLON, VDSEL, and VADSEL registers, it does not
actually exercise power supply control by these registers. Be sure to refer to the technical manual for
the S1C63158/358/P366 when setting the correct voltage. Also, when switching the control voltages,
consult the technical manual to determine the appropriate wait time to be inserted.
- Although this board has a control (VLCD) for adjusting the LCD drive voltage, the actual IC does
not have this capability. Note that the LCD drive voltage on this board may not be identical to that
on the actual IC.
- Since the usable operating frequency range depends on the device's internal operating voltage,
consult the technical manual for the S1C63158/358/P366 to ensure that the device will not be
operated with an inappropriate combination of the operating frequency and the internal power
supply.
<Differences in I/O registers>
Although the register bit D1 (address FF01H) is always set to 0 when read out, it operates as a read/
write register on this board. Take care to avoid writing a 1 to this bit.