mc68hc05l25 Freescale Semiconductor, Inc, mc68hc05l25 Datasheet - Page 120

• Manufacturer Part Number: mc68hc05l25
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Event Counter
The above example illustrates the relation of the gate signal to external oscillator clocks for the case of
MT3–MT0 = $1.
The beginning of the gate signal can be caused by a write to the event counter timing register or expiration
of the wait time. If the event counter timing register is written, the rising edge of the gate signal will occur
120
SYSTEM
CLOCK
DATA &
INTERRUPT
CLEAR
GATE
SIGNAL
NOTE: MT3 THROUGH MT0 = –$X1
NOTE: SYS0 and SYS1 = 00, f
MT3:MT0
WT3:WT0
$0X ms
$1X ms
$2X ms
$3X ms
$4X ms
$5X ms
$6X ms
$7X ms
1
$X0
$X1
$X2
$X3
$X4
$X5
$X6
$X7
Figure 13-5. Event Counter Gate Signal Timing Example
2
EVTR WRITE
3
Measurement Time
Table 13-1. Measurement Time Nibble
4
3.9063 ms
7.8125 ms
11.719 ms
15.625 ms
19.531 ms
23.438 ms
27.344 ms
Wait Time
3.9063 ms
7.8125 ms
11.719 ms
15.625 ms
19.531 ms
23.438 ms
27.344 ms
MC68HC05L25 Data Sheet, Rev. 3.1
Table 13-2. Wait Time Nibble
0 ms
0 ms
osc
= 4.1943 MHz
1
WT3:WT0
MT3:MT0
$BX
$CX
$DX
$EX
$XC
$XD
$Ax
$FX
$X8
$X9
$XA
$XB
$XE
$XF
$8x
$9x
2
. . .
. . .
. . .
Measurement Time
Wait Time
31.250 ms
35.156 ms
39.063 ms
42.969 ms
46.875 ms
50.781 ms
54.688 ms
58.593 ms
31.250 ms
35.156 ms
39.063 ms
42.969 ms
46.875 ms
50.781 ms
54.688 ms
58.593 ms
16,384
Freescale Semiconductor
16,385