
cycle, you must set the rselodd control bit to 1 to achieve this duty cycle despite an odd division factor.
When you set rselodd = 1, subtract 0.5 cycles from the high time and add 0.5 cycles to the low time.
The calculation for the example is shown as follows:
• High time count = 2 cycles
• Low time count = 1 cycle
• rselodd = 1 effectively equals:
• High time count = 1.5 cycles
• Low time count = 1.5 cycles
• Duty cycle = (1.5/3)% high time count and (1.5/3)% low time count
Related Information
Programmable Duty Cycle on page 2-19
Scan Chain
The MAX 10 PLLs have a 144-bit scan chain.
Table 4-1: PLL Component Reprogramming Bits
Block Name
Number of Bits
Counter Control Bit Total
C4
(6)
16 2
(7)
18
C3 16 2
(7)
18
C2 16 2
(7)
18
C1 16 2
(7)
18
C0 16 2
(7)
18
M 16 2
(7)
18
N 16 2
(7)
18
Charge Pump 9 0 9
Loop Filter
(8)
9 0 9
Total number of bits 144
(6)
LSB bit for C4 low-count value is the first bit shifted into the scan chain.
(7)
These two control bits include rbypass, for bypassing the counter, and rselodd, for selecting the output
clock duty cycle.
(8)
MSB bit for loop filter is the last bit shifted into the scan chain.
4-12
Scan Chain
UG-M10CLKPLL
2015.05.04
Altera Corporation
MAX 10 Clocking and PLL Implementation Guides
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