ADSP-21266SKBC-2B AD [Analog Devices], ADSP-21266SKBC-2B Datasheet - Page 19

• Manufacturer Part Number: ADSP-21266SKBC-2B
• Description: SHARC Embedded Processor
• Manufacturer: AD [Analog Devices]

Clock Input
See
Table 11. Clock Input
1
2
3
Clock Signals
The ADSP-21266 can use an external clock or a crystal. See
CLKIN pin description. The programmer can configure the
ADSP-21266 to use its internal clock generator by connecting
the necessary components to CLKIN and XTAL.
the component connections used for a crystal operating in fun-
damental mode. Note that the 200 MHz clock rate is achieved
using a 12.5 MHz crystal and a PLL multiplier ratio 16:1
(CCLK:CLKIN).
Parameter
Timing Requirements
t
t
t
t
t
Applies only for CLKCFG1
Applies only for CLKCFG1
Any changes to PLL control bits in the PMCTL register must meet core clock timing specification t
CK
CKL
CKH
CKRF
CCLK
CLKIN
NOTE: C1 AND C2 ARE SPECIFIC TO CRYSTAL SPECIFIED FOR X1.
CONTACT CRYSTAL MANUFACTURER FOR DETAILS. CRYSTAL
SELECTION MUST COMPLY WITH CLKCFG1-0 = 10 OR = 01.
Table 11
Figure 8. 150 MHz or 200 MHz Operation with a 12.5 MHz
C1
CLKIN
CLKIN Period
CLKIN Width Low
CLKIN Width High
CLKIN Rise/Fall (0.4 V – 2.0 V)
CCLK Period
and
Figure
Fundamental Mode Crystal
–
–
3
1M
X1
Figure 7. Clock Input
0 = 00 and default values for PLL control bits in PMCTL.
0 = 01 and default values for PLL control bits in PMCTL.
t
7.
CKH
C2
XTAL
t
CK
150 MHz
Min
20
7.5
7.5
6.66
t
CKL
1
1
1
Figure 8
Rev. B | Page 19 of 44 | May 2005
shows
Max
160
80
80
3
10
2
2
2
200 MHz
Min
15
6
6
5
1
1
CCLK
1
.
Max
160
80
80
3
10
2
2
2
Unit
ns
ns
ns
ns
ns
ADSP-21266