ADUC7060 Datasheet, PDF (66/108 Pages) Analog Devices – Low Power, Precision Analog Microcontroller, Dual Sigma-Delta ADCs, Flash/EE, ARM7TDMI

ADuC7060/ADuC7061
TIMER0
Timer0 is a 32-bit, general-purpose timer, count down or count
up, with a programmable prescaler. The prescaler source can be
the low power 32.768 kHz oscillator, the core clock, or from one
of two external GPIOs. This source can be scaled by a factor of
1, 16, 256, or 32,768. This gives a minimum resolution of 97.66 ns
with a prescaler of 1 (ignoring the external GPIOs).
The counter can be formatted as a standard 32-bit value or as
hours:minutes:seconds:hundredths.
Timer0 has a capture register (T0CAP) that is triggered by a
selected IRQ source initial assertion. When triggered, the current
timer value is copied to T0CAP, and the timer continues to run.
Use this feature to determine the assertion of an event with
increased accuracy. Note that only peripherals that have their
IRQ source enabled can be used with the timer capture feature.
The Timer0 interface consists of five MMRS: T0LD, T0VAL,
T0CAP, T0CLRI, and T0CON.
• T0LD, T0VAL, and T0CAP are 32-bit registers and hold
32-bit, unsigned integers of which T0VAL and T0CAP are
read only.
• T0CLRI is an 8-bit register and writing any value to this
register clears the Timer0 interrupt.
• T0CON is the configuration MMR, which is described in
Table 79.
Timer0 features a postscaler that allows the user to count between
1 and 256 the number of Timer0 timeouts. To activate the post-
scaler, the user sets Bit 18 and writes the desired number to count
into Bits[24:31] of T0CON. When that number of timeouts is
reached, Timer0 can generate an interrupt if T0CON[18] is set.
Note that, if the part is in a low power mode and Timer0 is
clocked from the GPIO or low power oscillator source, Timer0
continues to operate.
Timer0 reloads the value from T0LD when Timer0 overflows.
Timer0 Load Registers
Name:
T0LD
Address:
0xFFFF0320
Default value: 0x00000000
Access:
Read and write
Function:
T0LD is a 32-bit register that holds the 32-bit
value that is loaded into the counter.
Timer0 Clear Register
Name:
T0CLRI
Address:
0xFFFF032C
Access:
Write only
Function:
This 8-bit, write-only MMR is written
(with any value) by user code to clear the
interrupt.
Timer0 Value Register
Name:
T0VAL
Address:
0xFFFF0324
Default value: 0xFFFFFFFF
Access:
Read only
Function:
T0VAL is a 32-bit register that holds the
current value of Timer0.
32.768kHz OSCILLATOR
CORE CLOCK
FREQUENCY/CD
CORE CLOCK
FREQUENCY
GPIO
32-BIT LOAD
PRESCALER
1, 16, 256, OR 32,768
32-BIT
UP/DOWN COUNTER
IRQ[31:0]
CAPTURE
TIMER0
VALUE
8-BIT
POSTSCALER
TIMER0 IRQ
Figure 23. Timer0 Block Diagram
Rev. B | Page 66 of 108