High-Speed Differential I/O with DPA Support
For high-speed source synchronous interfaces such as POS-PHY 4,
Parallel RapidIO, and HyperTransport, the source synchronous clock rate
is not a byte- or SERDES-rate multiple of the data rate. Byte alignment is
necessary for these protocols since the source synchronous clock does not
provide a byte or word boundary since the clock is one half the data rate,
not one eighth. The Stratix II device’s high-speed differential I/O
circuitry provides dedicated data realignment circuitry for user-
controlled byte boundary shifting. This simplifies designs while saving
ALM resources. You can use an ALM-based state machine to signal the
shift of receiver byte boundaries until a specified pattern is detected to
indicate byte alignment.
Fast PLL & Channel Layout
The receiver and transmitter channels are interleaved such that each I/O
bank on the left and right side of the device has one receiver channel and
one transmitter channel per LAB row. Figure 2–60 shows the fast PLL and
channel layout in the EP2S15 and EP2S30 devices. Figure 2–61 shows the
fast PLL and channel layout in the EP2S60 to EP2S180 devices.
Figure 2–60. Fast PLL & Channel Layout in the EP2S15 & EP2S30 Devices Note (1)
4
4
LVDS
Clock
DPA
Clock
DPA
Clock
LVDS
Clock
Quadrant
Quadrant
4
4
2
2
2
2
Fast
PLL 1
Fast
PLL 4
Fast
PLL 2
Fast
PLL 3
Quadrant
Quadrant
LVDS
Clock
DPA
Clock
DPA
Clock
LVDS
Clock
4
4
Note to Figure 2–60:
(1) See Table 2–21 for the number of channels each device supports.
2–102
Altera Corporation
May 2007
Stratix II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
