![](http://datasheet.mmic.net.cn/Analog-Devices-Inc/ADUC836BCPZ_datasheet_96322/ADUC836BCPZ_70.png)
ADuC836
–70–
ADuC836
–71–
TIMING SPECIFICATIONS1, 2, 3 (AVDD = 2.7 V to 3.6 V or 4.75 V to 5.25 V, DVDD = 2.7 V to 3.6 V or 4.75 V to 5.25 V;
all specifications TMIN to TMAX, unless otherwise noted.)
32.768 kHz External Crystal
Parameter
Min
Typ
Max
Unit
CLOCK INPUT (External Clock Driven XTAL1)
tCK
XTAL1 Period
30.52
s
tCKL
XTAL1 Width Low
6.26
s
tCKH
XTAL1 Width High
6.26
s
tCKR
XTAL1 Rise Time
9
s
tCKF
XTAL1 Fall Time
9
s
1/tCORE
ADuC836 Core Clock Frequency4
0.098
12.58
MHz
tCORE
ADuC836 Core Clock Period5
0.636
s
tCYC
ADuC836 Machine Cycle Time6
0.95
7.6
122.45
s
NOTES
1AC inputs during testing are driven at DVDD – 0.5 V for a Logic 1, and 0.45 V for a Logic 0.Timing measurements are made at VIH min for a Logic 1, and VIL max for a
Logic 0, as shown in Figure 70.
2For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage occurs. A port pin begins to float when a 100 mV change from the loaded
VOH/VOL level occurs, as shown in Figure 70.
3CLOAD for Port 0, ALE, PSEN outputs = 100 pF; CLOAD for all other outputs = 80 pF, unless otherwise noted.
4ADuC836 internal PLL locks onto a multiple (384 times) the external crystal frequency of 32.768 kHz to provide a stable 12.583 MHz internal clock for the system.
The core can operate at this frequency or at a binary submultiple called Core_Clk, selected via the PLLCON SFR.
5This number is measured at the default Core_Clk operating frequency of 1.57 MHz.
6ADuC836 Machine Cycle Time is nominally defined as 12/Core_Clk.
tCKH
tCKL
tCK
tCKF
tCKR
Figure 69. XTAL1 Input
DVDD – 0.5V
0.45V
0.2DVDD + 0.9V
TEST POINTS
0.2DVDD – 0.1V
VLOAD – 0.1V
VLOAD
VLOAD + 0.1V
TIMING
REFERENCE
POINTS
VLOAD – 0.1V
VLOAD
VLOAD + 0.1V
Figure 70.Timing Waveform Characteristics
REV. A