NEC IE-789860-NS-EM1, Руководство пользователя

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CHAPTER 3 INSTALLATION
User’s Manual U16499EJ1V0UM
22
3.4 Clock Settings
3.4.1 Overview of clock settings
The system clock 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 the 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 3-3.
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 in the IE-78K0S-NS or IE-78K0S-NS-A is used.
If the target system includes an external clock, select either (1) Clock that is already mounted on emulation
board , (2) Clock that is mounted by user , or (3) Pulse input from target system . For the external clock, a clock
signal is supplied from outside of 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 3-3.
Caution The IE system will be hung-up if the main system clock is not supplied normally. Moreover, be
sure to input a rectangular wave as the pulse from the target system. There is no need to
supply a clock to the X2 pin. Also, even if a crystal resonator is connected directly to X1 (for
the main system clock), the target device will not operate. When emulating the
µµµµ
PD789861
Subseries, RC oscillation cannot be used.
Figure 3-3. External Circuits Used as System Clock Oscillator
(a) Clock oscillator (b) External clock
X1
Crystal or ceramic
resonator
V
SS
External
clock
X2
X1
X2
Target device Target device