Atmel Evaluation Kit for AT32uC3A0512, 32-Bit AVR Microcontroller Atmel ATEVK1105 ATEVK1105 Data Sheet
Product codes
ATEVK1105
69
AT32UC3A
13.6.2
Clock Select
Name:
CKSEL
Access Type:
Read/Write
•
PBBDIV, PBBSEL: PBB Division and Clock Select
PBBDIV = 0: PBB clock equals main clock.
PBBDIV = 1: PBB clock equals main clock divided by 2
PBBDIV = 1: PBB clock equals main clock divided by 2
(PBBSEL+1)
.
•
PBADIV, PBASEL: PBA Division and Clock Select
PBADIV = 0: PBA clock equals main clock.
PBADIV = 1: PBA clock equals main clock divided by 2
PBADIV = 1: PBA clock equals main clock divided by 2
(PBASEL+1)
.
•
HSBDIV, HSBSEL: HSB Division and Clock Select
For the AT32UC3A, HSBDIV always equals CPUDIV, and HSBSEL always equals CPUSEL, as the HSB clock is always equal to
the CPU clock.
the CPU clock.
•
CPUDIV, CPUSEL: CPU Division and Clock Select
CPUDIV = 0: CPU clock equals main clock.
CPUDIV = 1: CPU clock equals main clock divided by 2
CPUDIV = 1: CPU clock equals main clock divided by 2
(CPUSEL+1)
.
Note that if xxxDIV is written to 0, xxxSEL should also be written to 0 to ensure correct operation.
Also note that writing this register clears POSCSR:CKRDY. The register must not be re-written until CKRDY goes high.
Also note that writing this register clears POSCSR:CKRDY. The register must not be re-written until CKRDY goes high.
31
30
29
28
27
26
25
24
PBBDIV
-
-
-
-
PBBSEL
23
22
21
20
19
18
17
16
PBADIV
-
-
-
-
PBASEL
15
14
13
12
11
10
9
8
HSBDIV
-
-
-
-
HSBSEL
7
6
5
4
3
2
1
0
CPUDIV
-
-
-
-
CPUSEL
32058K
AVR32-01/12