Altera Serial Digital Interface (SDI) MegaCore Function - Manual (Page 65)

Chapter 3: Functional Description 3–35
Block Description
February 2013 Altera Corporation Serial Digital Interface (SDI) MegaCore Function
User Guide
ALTPLL_RECONFIG Connections
Figure 3–21 shows the handshaking between the SDI MegaCore function and the
reconfig control logic, and the expected output of some of the ALTPLL_RECONFIG
signals.
The following sequence of events occur for handshaking to the reconfiguration logic:
1. The SDI MegaCore function sets rx_std[1:0] to the desired video standard. This
action is performed as part of the video standards detection algorithm.
2. The SDI MegaCore function asserts SDI_START_RECONFIG to make a
reconfiguration request.
3. The reconfig control logic sets WRITE_FROM_ROM line to 1, and signals the
ALTPLL_RECONFIG megafunction to write from the ROM.
4. The reconfig control logic asserts the PLL_RECONFIG line to 1, and signals the
ALTPLL_RECONFIG megafunction to start the reconfiguration process.
5. When the reconfiguration has been performed, the transceiver’s PLL asserts the
output signal, PLL_SCANDONE, to the ALTPLL_RECONFIG megafunction indicating
that the PLL is reconfigured, and internally indicates to the SDI MegaCore
function to start locking to the incoming data.
6. The SDI MegaCore function sets the SDI_START_RECONFIG line to 0 to indicate that
the request is completed and acknowledged.
Figure 3–23. Handshaking between SDI MegaCore Function and ALTPLL_RECONFIG Signals
SDI_START_RECONFIG
RX_STD[1:0] 11 01
PLL_ARESET
PLL_CONFIGUPDATE
PLL_SCANCLK
PLL_SCANCLKENA
PLL_SCANDATA
PLL_SCANDATAOUT
PLL_SCANDONE
PLL_RECONFIG
RESET_ROM_ADDRESS
ROM_DATA_IN
WRITE_FROM_ROM
BUSY
WRITE_ROM_ENA
ROM_ADDRESS_OUT
2
3 4 5
6 1