CHAPTER 3 INSTALLATION
User’s Manual U16290EJ1V0UM
23
3.4
Clock Settings
3.4.1 Overview of clock settings
The main system and subsystem clocks to be used during debugging can be selected from (1) to (3) below.
(1) Clock that is already mounted on emulation board
(2) Clock that is mounted by user
(3) Pulse input from target system
If the target system includes a clock oscillator, select either
(1) Clock that is already mounted on emulation
board
or
(2) Clock that is mounted by user
. For a clock oscillator, a resonator is connected to the target device
and the target device’s internal oscillator is used. An example of the external circuit is shown in part (a) of Figure 3-5.
During emulation, the oscillator that is mounted on the target system is not used. Instead, the clock that is mounted
on the emulation board installed for the IE-78K0S-NS or IE-78K0S-NS-A is used.
If the target system includes an external clock, select
(1) Clock that is already mounted on emulation board
,
(2) Clock that is mounted by user
, or
(3) Pulse input from target system
. For an external clock, a clock signal is
supplied from outside the target device and the target device’s internal oscillator is not used. An example of the
external circuit is shown in part (b) of Figure 3-5.
Caution
The IE system will be hung-up if the main system clock is not supplied normally. Emulating
using the RC oscillator is not possible. Moreover, be sure to input a rectangular wave as the
clock from the target. However, there is no need to supply clocks to the X2 and XT2 pins. The
IE system does not operate if a crystal resonator or ceramic resonator is directly connected to
the X1 or XT1 pin.
Figure 3-5. External Circuits Used as System Clock Oscillator
(a) Clock oscillator
(b) External clock
X1 or XT1
V
SS
External
clock
X2 or XT2
X1 or XT1
X2 or XT2
Target device
Target device
Crystal resonator
or
ceramic oscillator
