REV. 0
ADuC816
–8–
TIMING SPECIFICATIONS
1, 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
Figure
CLOCK INPUT (External Clock Driven XTAL1)
tCK
XTAL1 Period
30.52
μs1
tCKL
XTAL1 Width Low
15.16
μs1
tCKH
XTAL1 Width High
15.16
μs1
tCKR
XTAL1 Rise Time
20
ns
1
tCKF
XTAL1 Fall Time
20
ns
1
1/tCORE
ADuC816 Core Clock Frequency
4
0.098
12.58
MHz
tCORE
ADuC816 Core Clock Period
5
0.636
μs
tCYC
ADuC816 Machine Cycle Time
6
0.95
7.6
122.45
μs
NOTES
1AC inputs during testing are driven at DV
DD – 0.5 V for a Logic 1, and 0.45 V for a Logic 0. Timing measurements are made at V IH min for a Logic 1, and VIL max
for a Logic 0 as shown in Figure 2.
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 2.
3C
LOAD for Port0, ALE,
PSEN outputs = 100 pF; CLOAD for all other outputs = 80 pF unless otherwise noted.
4ADuC816 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.
6ADuC816 Machine Cycle Time is nominally defined as 12/Core_CLK.
Specifications subject to change without notice.
t
CHK
t
CKL
t
CK
t
CKF
t
CKR
Figure 1. 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 2. Timing Waveform Characteristics
REV. A