ATAM894X-TNQY ATMEL [ATMEL Corporation], ATAM894X-TNQY Datasheet - Page 18

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

5.5.2.3
5.5.2.4
18
ATAM894
RC-oscillator 2 with External Trimming Resistor
4-MHz Oscillator
Table 5-5.
The RC-oscillator 2 is a high resolution trimmable oscillator whereby the oscillator frequency can
be trimmed with an external resistor between OSC1 and V
lator 2 frequency can be maintained stable with a tolerance of ±15% over the full operating
temperature and a voltage range V
For example: An output frequency at the RC-oscillator 2 of 2 MHz can be obtained by connect-
ing a resistor R
Figure 5-15. RC-oscillator 2
The ATAM894 4-MHz oscillator options need a crystal or ceramic resonator connected to the
OSC1 and OSC2 pins to establish oscillation. All the necessary oscillator circuitry, with the
exception of the actual crystal, resonator, C
Figure 5-16. 4-MHz Crystal Oscillator
Note:
OS1
Both, the 4-MHz and the 32-kHz crystal oscillator, use an integrated 14 stage divider circuit to sta-
bilize oscillation before the oscillator output is used as system clock. This results in an additional
delay of about 4 ms for the 4-MHz crystal and about 500 ms for the 32-kHz crystal.
1
1
x
Supervisor Function Control Bits
ext
= 360 k (see
OS0
1
1
0
configurable
V
OSC1
OSC2
R
DD
ext
*
4 MHz
XTAL
OSC1
OSC2
Figure
DD
from 2.5V to 6.0V.
5-15).
RC-oscillator 2
R
CCS
*
C
*
C
Trim
3
1
2
0
1
x
and C
Oscin
Oscout
RcOut2
oscillator
4-MHz
Stop
4
are integrated on-chip.
4Out
Stop
DD
Supervisor Reset Output (Res)
. In this configuration, the RC-oscil-
Osc-Stop
RcOut2
Osc-Stop
4Out
Disable
Disable
Enable
4679D–4BMCU–05/05