ATAM893X-TKHYZ ATMEL [ATMEL Corporation], ATAM893X-TKHYZ Datasheet - Page 16

• Manufacturer Part Number: ATAM893X-TKHYZ
• Description: Flash Version for ATAR080, ATAR090/890 and ATAR092/892
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 4-12. Clock Module
16
OSC1
OSC2
ATAM893-D
*
*
*
configurable
Oscin
Oscout
RC oscillator 2
R
4-MHz oscillator
Oscin
Oscin
Ext. clock
ExIn
Oscout
32-kHz oscillator
Oscout
Trim
The clock module is programmable via software with the clock management register (CM) and
the system configuration register (SC). The required oscillator configuration can be selected with
the OS1 bit and the OS0 bit in the SC register. A programmable 4-bit divider stage allows the
adjustment of the system clock speed. A special feature of the clock management is that an
external oscillator may be used and switched on and off via a port pin for the power-down mode.
Before the external clock is switched off, the internal RC-oscillator 1 must be selected with the
CCS bit and then the SLEEP mode may be activated. In this state an interrupt can wake up the
controller with the RC-oscillator, and the external oscillator can be activated and selected by
software. A synchronization stage avoids clock periods that are too short if the clock source or
the clock speed is changed. If an external input clock is selected, a supervisor circuit monitors
the external input and generates a hardware reset if the external clock source fails or drops
below 500 kHz for more than 1 ms.
Table 4-4.
The clock module generates two output clocks. One is the system clock (SYSCL) and the other
the periphery (SUBCL). The SYSCL can supply the core and the peripherals and the SUBCL
can supply only the peripherals with clocks. The modes for clock sources are programmable
with the OS1 bit and OS0 bit in the SC register and the CCS bit in the CM register.
SC
Mode
1
2
3
4
BOT
RCOut2
ExOut
32Out
OS1
4Out
- - -
Stop
Stop
Stop
1
0
1
0
Clock Modes
OS1
OS0
1
1
0
0
OS0
Osc-Stop
Stop
oscillator 1
RC-oscillator 1 (intern)
RC-oscillator 1 (intern)
RC-oscillator 1 (intern)
RC-oscillator 1 (intern)
RC-
CM
RCOut1
Control
NSTOP
CCS = 1
IN1
IN2
Sleep
WDL
Clock Source for SYSCL
CCS
Cin
CSS1
/2
CSS0
RC-oscillator 2 with external
/2
External input clock
trimming resistor
32-kHz oscillator
Divider
4-MHz oscillator
CCS = 0
/2
32 kHz
Cin/16
/2
Clock Source for
4680C–4BMCU–01/05
SYSCL
SUBCL
SUBCL
32 kHz
C
C
C
in
in
in
/16
/16
/16