ATAM894X-TNQY ATMEL [ATMEL Corporation], ATAM894X-TNQY Datasheet - Page 15

• Manufacturer Part Number: ATAM894X-TNQY
• Description: 8k-flash Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

5.5
5.5.1
4679D–4BMCU–05/05
Clock Generation
Clock Module
VIM
VMS
Figure 5-10. Internal Supply Voltage Supervisor
Figure 5-11. External Input Voltage Supervisor
The ATAM894 contains a clock module with 4 different internal oscillator types: two RC-oscilla-
tors, one 4-MHz crystal oscillator and one 32-kHz crystal oscillator. The pins OSC1 and OSC2
are the interface to connect a crystal either to the 4-MHz, or to the 32-kHz crystal oscillator.
OSC1 can be used as input for external clocks or to connect an external trimming resistor for the
RC-oscillator 2. All necessary circuitry except the crystal and the trimming resistor is integrated
on-chip. One of these oscillator types or an external input clock can be selected to generate the
system clock (SYSCL).
In applications that do not require exact timing, it is possible to use the fully integrated RC-oscil-
lator 1 without any external components. The RC-oscillator 1 center frequency tolerance is
better than ±50%. The RC-oscillator 2 is a trimmable oscillator whereby the oscillator frequency
can be trimmed with an external resistor attached between OSC1 and V
the RC-oscillator 2 frequency can be maintained stable to within a tolerance of ±15% over the
full operating temperature and voltage range.
3.0 V
2.6 V
2.2 V
V
1.3 V
VMI
DD
VMS = 1
V oltage I nterrupt M ask bit
VIM = 0, voltage monitor interrupt is enabled
VIM = 1, voltage monitor interrupt is disabled
V oltage M onitor S tatus bit
VMS = 0, the voltage at the comparator input is below V
VMS = 1, the voltage at the comparator input is above V
Low threshold
Middle threshold
High threshold
Negative slope
Positive slope
VMS = 1
VMS = 0
Internal reference level
Interrupt positive slope
Interrupt negative slope
VMS = 1
VMS = 0
Low threshold
Middle threshold
High threshold
DD
. In this configuration,
VMS = 0
ATAM894
Ref
Ref
t
15