HC4GX15 Datasheet, PDF (457/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV GX Transceiver Architecture
Calibration Blocks
1–193
Figure 1–162 shows HardCopy IV GX device families that have three transceiver
blocks each on the left and right side.
Figure 1–162. Calibration Block Locations in HardCopy IV GX Device Families with Three-Transceiver
Blocks (on Each Side)
2K Ω
Calibration
Block L1
Calibration
2K Ω
Block R1
GXBL2
GXBL1
GXBL0
GXBR2
HardCopy IV GX
Device
GXBR1
GXBR0
Calibration
Calibration
Block L0
2K Ω
Calibration
Block R0
2K Ω
Figure 1–163 shows HardCopy IV GX device families that have two transceiver blocks
only on the right side of the device.
Figure 1–163. Calibration Two Transceiver Blocks, Right Side Only
GXBR1
HardCopy IV GX
Device
GXBR0
Calibration Block
R0
2K Ω
The Quartus II software automatically selects the appropriate calibration block based
on the assignment of the transceiver tx_dataout and rx_datain pins.
The calibration block internally generates a constant internal reference voltage,
independent of process, voltage, or temperature variations. It uses the internal
reference voltage and external reference resistor (you must connect the resistor to the
RREF pin) to generate constant reference currents. These reference currents are used
by the analog block calibration circuit to calibrate the transceiver blocks.
The OCT calibration circuit calibrates the OCT resistors present in the transceiver
channels. You can enable the OCT resistors in the transceiver channels through the
ALTGX MegaWizard Plug-In Manager.
© June 2009 Altera Corporation
HardCopy IV Device Handbook Volume 3