ATA6617 View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
ATA6617
Atmel Corporation
'ATA6617' PDF : 308 Pages View PDF
• Bits 3:0 – CLKC3:0: Clock Control Bits 3 - 0
These bits define the command to provide to the ‘Clock Switch’ module. The special write pro-
cedure must be followed to change the CLKC3..0 bits (See ”Bit 7 – CLKCCE: Clock Control
Change Enable” on page 63.).
1. Write the Clock Control Change Enable (CLKCCE) bit to one and all other bits in
CLKCSR to zero.
2. Within 4 cycles, write the desired value to CLKCSR register while clearing CLKCCE
bit.
Interrupts should be disabled when setting CLKCSR register in order not to disturb the
procedure.
4.5.5.4
Table 4-15. Clock Command List
Clock Command
No command
Disable clock source
Enable clock source
Request for clock availability
Clock source switch
Recover system clock source code
Enable watchdog in automatic reload mode
CKOUT command
No command
CLKSELR - Clock Selection Register
CLKC3..0
0000 b
0001 b
0010 b
0011 b
0100 b
0101 b
0110 b
0111 b
1xxx b
Bit
7
6
5
4
3
2
1
0
-
COUT CSUT1 CSUT0 CSEL3 CSEL2 CSEL1 CSEL0 CLKSELR
Read/Write
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
~ (CKOUT)
SUT1..0
CKSEL3..0
fuse
fuses
fuses
• Bit 7– Res: Reserved Bit
This bit is reserved bit in the Atmel® ATtiny87/167 and will always read as zero.
• Bit 6 – COUT: Clock Out
The COUT bit is initialized with ~(CKOUT) Fuse bit.
The COUT bit is only used in case of ‘CKOUT’ command. Refer to Section 4.5.2.7 “Clock Out-
put Buffer” on page 55 for using.
In case of ‘Recover System Clock Source’ command, COUT it is not affected (no recovering of
this setting).
• Bits 5:4 – CSUT1:0: Clock Start-up Time
CSUT bits are initialized with the values of SUT Fuse bits.
In case of ‘Enable/Disable Clock Source’ command, CSUT field provides the code of the clock
start-up time. Refer to subdivisions of Section 4.5.2 “Clock Sources” on page 49 for code of
clock start-up times.
In case of ‘Recover System Clock Source’ command, CSUT field is not affected (no recover-
ing of SUT code).
64 Atmel ATA6616/ATA6617
9132D–AUTO–12/10
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