Altera Serial Digital Interface (SDI) MegaCore Function - Manual (Page 62)

3–32 Chapter 3: Functional Description
Block Description
Serial Digital Interface (SDI) MegaCore Function February 2013 Altera Corporation
User Guide
The transceiver megafunction is embedded inside the SDI MegaCore function. The
reprogramming ports (reconfig_togxb[3:0] and reconfig_fromgxb[<(N×16)-1>:0])
for the transceiver megafunction are brought to the top-level interfaces of the
MegaCore function. This interface only connects to the ALT2GXB_RECONFIG or
ALTGX_RECONFIG block.
Figure 3–19 shows the block diagram of how the SDI MegaCore function and the
ALT2GXB_RECONFIG megafunction are connected when you use the transmitter
clock multiplexer feature.
When enabling the transmitter clock multiplexer feature, the ALT2GXB_RECONFIG
block handles the programming of the ROM contents to the transceiver megafunction.
The ROM holds the information setting for the default reference clock selection of the
TX PLL in the transmitter, as well as the values of the logical_tx_pll_sel and
logical_tx_pll_sel_en
pins. The reconfiguration control and intercept user logic
block detects changes in the trigger port, sets the logical_tx_pll_sel and
logical_tx_pll_sel_en
to the corresponding value, and initiates the reprogramming
of the transmitter megafunction.
ALT2GXB_RECONFIG Connections for Receiver
The SDI_START_RECONFIG and SDI_RECONFIG_DONE signals handle the handshaking
between the SDI MegaCore function and the user logic. The RX_STD signal must select
the correct transceiver setting.
1 Table 3–19 on page 3–54 lists the five signals that handle transceiver dynamic
reconfiguration.
Figure 3–20. Transceiver Dynamic Reconfiguration for Transmitter Clock Multiplexer Block Diagram
ALT2GXB
RECONFIG_INST
RECONFIG Control
and Intercept
User Logic
RECONFIG_TOGXB[2:0]
ROM_CLK_ENABLE
ROM_ADDRESS
ROM_DATA_OUT
TX_PLL_SELECT Transmitter
only
User Logic
Encrypted RECONFIG Megafunction
Encrypted SDI IP Core
ROM (Hold MIF)
RECONFIG_FROMGXB[0]
SDI_RECONFIG_DONE
SDI_START_RECONFIG
ALT2GXB_INST
Protocol
SDI IP Core - Duplex
ALT2GXB_INST
Protocol
SDI IP Core - Transmitter