ep3c120f780c8nes Altera Corporation, ep3c120f780c8nes Datasheet - Page 448

• Manufacturer Part Number: ep3c120f780c8nes
• Description: Cyclone Iii Device Family
• Manufacturer: Altera Corporation

I/O Timing
1–38
Cyclone III Handbook
3.3-V LVTTL
3.3V LVCMOS
3.0-V LVTTL
3.0-V LVCMOS
2.5-V LVTTL/LVCMOS
Table 1–43. Maximum Input Clock Toggle Rate on Cyclone III Devices (Part 1 of 3)
I/O Standard
Speed
Grade
Maximum Input & Output Clock Toggle Rate
The maximum clock toggle rate is defined as the maximum frequency
achievable for a clock type signal at an I/O pin. The I/O pin can be a
regular I/O pin or a dedicated clock I/O pin.
The maximum clock toggle rate is different from the maximum data bit
rate. If the maximum clock toggle rate on a regular I/O pin is 300 MHz,
the maximum data bit rate for dual data rate (DDR) could be potentially
as high as 600 Mbps on the same I/O pin.
Table 1–43
specifies the maximum output clock toggle rates at 0 pF load.
specifies the derating factors for the output clock toggle rate for a non 0
pF load.
To calculate the output toggle rate for a non 0 pF load, use this formula:
The toggle rate for a non 0 pF load
For example, the output toggle rate at 0 pF load for SSTL-18 Class II 16
I/O standard is 260 MHz on a -6 device clock output pin. The derating
factor is 26 ps/pF. For a 10 pF load the toggle rate is calculated as:
Table 1–43
devices.
450
450
450
(1)
(1)
-6
Column I/O Pins
= 1000 / (1000/ toggle rate at 0 pF load + derating factor * load value
in pF /1000)
1000 / (1000/260 + 26 x 10 /1000) = 243 (MHz)
Maximum Input Clock Toggle Rate on Cyclone III Devices (MHz)
Speed
Grade
405
405
405
(1)
(1)
-7
specifies the maximum input clock toggle rates.
through
Speed
Grade
360
360
360
(1)
(1)
-8
Table 1–45
Speed
Grade
450
450
450
(1)
(1)
-6
Row I/O Pins
show the I/O toggle rates for Cyclone III
Speed
Grade
405
405
405
(1)
(1)
-7
Speed
Grade
360
360
360
(1)
(1)
Altera Corporation- Preliminary
-8
Speed
Grade
Dedicated Clock Inputs
420
420
450
(1)
(1)
-6
Speed
Grade
380
380
405
Preliminary
(1)
(1)
Table 1–44
-7
March 2007
Table 1–45
Speed
Grade
340
340
360
(1)
(1)
-8
μA