Rev. 2.0, 11/00, page 229 of 1037
(2) External Clock
The external clock signal should have the same frequency as the system clock (
φ
).
Table 10.3 and figure 10.6 show the input conditions for the external clock.
Table 10.3 External Clock Input Conditions
V
CC
= 4.0 to 5.5 V
Item
Symbol
Min
Max
Unit
Test Conditions
External clock input low
pulse width
t
CPL
40
ns
External clock input
high pulse width
t
CPH
40
ns
External clock rise time
t
CPr
10
ns
External clock fall time
t
CPf
10
ns
Figure 10.6
t
CPH
t
CPL
t
CPr
t
CPf
OSC1
Figure 10.6 External Clock Input Timing
Table 10.4 shows the external clock output settling delay time, and figure 10.7 shows the
external clock output settling delay timing. The oscillator and duty adjustment circuit have a
function for adjusting the waveform of the external clock input at the OSC1 pin. When the
prescribed clock signal is input at the OSC1 pin, internal clock signal output is fixed after the
elapse of the external clock output settling delay time (t
DEXT
). As the clock signal output is not
fixed during the t
DEXT
period, the reset signal should be driven low to maintain the reset state.
Содержание Hitachi H8S/2191
Страница 123: ...Rev 2 0 11 00 page 96 of 1037...
Страница 149: ...Rev 2 0 11 00 page 122 of 1037...
Страница 197: ...Rev 2 0 11 00 page 170 of 1037...
Страница 247: ...Rev 2 0 11 00 page 220 of 1037...
Страница 249: ...Rev 2 0 11 00 page 222 of 1037...
Страница 347: ...Rev 2 0 11 00 page 320 of 1037...
Страница 357: ...Rev 2 0 11 00 page 330 of 1037...
Страница 417: ...Rev 2 0 11 00 page 390 of 1037...
Страница 431: ...Rev 2 0 11 00 page 404 of 1037...
Страница 439: ...Rev 2 0 11 00 page 412 of 1037...
Страница 457: ...Rev 2 0 11 00 page 430 of 1037...
Страница 525: ...Rev 2 0 11 00 page 498 of 1037...
Страница 543: ...Rev 2 0 11 00 page 516 of 1037...
Страница 639: ...Rev 2 0 11 00 page 612 of 1037 28 1 2 Block Diagram Figure 28 1 shows a block diagram of the servo circuits...
Страница 845: ...Rev 2 0 11 00 page 818 of 1037...