Data Sheet
ADuC7019/20/21/22/24/25/26/27/28/29
Example source code
Example source code
t2val_old= T2VAL;
T2LD = 5;
t2val_old= T2VAL;
T2LD = 5;
TCON = 0x480;
TCON = 0x480;
while ((T2VAL == t2val_old) || (T2VAL >
3)) //ensures timer value loaded
while ((T2VAL == t2val_old) || (T2VAL
> 3)) //ensures timer value loaded
IRQEN = 0x10;
//enable T2 interrupt
IRQEN = 0x10;
//enable T2 interrupt
PLLKEY1 = 0xAA;
PLLCON = 0x01;
PLLKEY2 = 0x55;
PLLKEY1 = 0xAA;
PLLCON = 0x03; //Select external clock
PLLKEY2 = 0x55;
POWKEY1 = 0x01;
POWCON = 0x27;
// Set Core into Nap mode
POWKEY1 = 0x01;
POWCON = 0x27;
// Set Core into Nap mode
POWKEY2 = 0xF4;
POWKEY2 = 0xF4;
In noisy environments, noise can couple to the external crystal
pins, and PLL may lose lock momentarily. A PLL interrupt is
provided in the interrupt controller. The core clock is immediately
halted, and this interrupt is only serviced when the lock is restored.
Power Control System
A choice of operating modes is available on the ADuC7019/20/
21/22/24/25/26/27/28/29. Table 57 describes what part is powered
on in the different modes and indicates the power-up time.
In case of crystal loss, the watchdog timer should be used. During
initialization, a test on the RSTSTA register can determine if the
reset came from the watchdog timer.
Table 58 gives some typical values of the total current consump-
tion (analog + digital supply currents) in the different modes,
depending on the clock divider bits. The ADC is turned off. Note
that these values also include current consumption of the
regulator and other parts on the test board where these values
are measured.
External Clock Selection
To switch to an external clock on P0.7, configure P0.7 in
Mode 1. The external clock can be up to 44 MHz, providing
the tolerance is 1%.
Table 57. Operating Modes1
Mode
Active
Pause
Nap
Sleep
Stop
Core
Peripherals
PLL
X
X
XTAL/T2/T3
IRQ0 to IRQ3
Start-Up/Power-On Time
130 ms at CD = 0
24 ns at CD = 0; 3 µs at CD = 7
24 ns at CD = 0; 3 µs at CD = 7
1.58 ms
X
X
X
X
X
X
X
X
X
X
X
X
X
1.7 ms
1 X indicates that the part is powered on.
Table 58. Typical Current Consumption at 25°C in Milliamperes
PC[2:0]
Mode
Active
Pause
Nap
CD = 0
33.1
22.7
3.8
CD = 1
21.2
13.3
3.8
CD = 2
13.8
8.5
CD = 3
10
6.1
CD = 4
8.1
4.9
CD = 5
7.2
4.3
CD = 6
6.7
4
CD = 7
6.45
3.85
3.8
000
001
010
3.8
3.8
3.8
3.8
3.8
011
100
Sleep
Stop
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
Rev. F | Page 59 of 104
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