SIC63616-(Rev. 1.0) NO. P217
3240-0412
(3) Functional precautions
<LCD driver>
The S1C6F632 chips included in the S5U1C6F632P2 board generate the LCD drive waveform. The
S5U1C6F632P2 has two on-board S1C6F632 chips and one of them is used for 1/4 bias drive and an-
other is used for 1/5 bias drive. Note that both the CN4 connector for 1/4 bias and CN4 connector for
1/5 bias on the S5U1C6F632P2 board output the LCD drive waveforms regardless of which option is
selected. The target board must be connected to the connector for the drive bias used in the application.
<SVD circuit>
- The SVD function is realized by artificially varying the power supply voltage using the VSVD control
on S5U1C63000P6. However, the S5U1C63000P6 supports detection of eight levels (0000B to 0111B)
only and the SVD3 register value is ignored (e.g. the same detection results are obtained when SVDS =
1111B and when SVDS = 0111B). The SVDS3 value should be checked with the monitor LED.
- There is a finite delay time from when the power to the SVD circuit turns on until actual detection
of the voltage. On S5U1C63000P6, there is no delay, which differs from that of the actual IC. Refer to
Chapter 7, "Electrical Characteristics", when setting the appropriate wait time for the actual IC.
<Oscillation circuit>
- A wait time is required before oscillation stabilizes after the OSC3 oscillation control circuit (OSCC) is
turned on. On S5U1C63000P6, even when OSC3 oscillation is changed (CLKCHG) without a wait time,
OSC3 will function normally. Refer to Chapter 7, "Electrical Characteristics", when setting the appro-
priate wait time for the actual IC.
- Use separate instructions to switch the clock from OSC3 to OSC1 and to turn off the OSC3 oscillation
circuit. If executed simultaneously with a single instruction, these operations, although good with
S5U1C63000P6, may not function properly well with the actual IC.
- Because the logic level of the oscillation circuit is high, the timing at which the oscillation starts on
S5U1C63000P6 differs from that of the actual IC.
- S5U1C63000P6 contains oscillation circuits for OSC1 and OSC3. Keep in mind that even though the
actual IC may not have a resonator connected to its OSC3, its emulator can operate with the OSC3
circuit.
- S5U1C63000P6 generates the OSC3 clock using the onboard CR oscillation circuit even if ceramic oscil-
lation is selected for the OSC3 oscillation circuit by mask option.
<Access to undefined address space>
If any undefined space in the S1C63616'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 S5U1C63000P6 and the actual IC. Note that the ICE (S5U1C63000H2/
S5U1C63000H6) 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 the peripheral circuit boards
(S5U1C63000P6 and S5U1C6F632P2) 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 S5U1C63000P6 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 performed by pressing the reset switch on S5U1C63000P6,
by a reset pin input, or by holding the input ports high simultaneously.
(* Free running mode: supported by S5U1C63000H1/2 only)