Serial Configuration Device Memory Access
Read Silicon ID Operation
The read silicon ID operation code is b'1010 1011, with the MSB listed
first. This operation reads the serial configuration device’s 8-bit silicon ID
from the DATAoutput pin. If this operation is shifted in during an erase
or write cycle, it will be ignored and have no effect on the cycle that is in
progress. Table 4–11 shows the EPCS1 and EPCS4 device silicon IDs.
Table 4–11. Serial Configuration Device Silicon ID
Serial Configuration Device
Silicon ID (Binary Value)
b'0001 0000
EPCS1
EPCS4
b'0001 0010
The device implements the read silicon ID operation by driving nCSlow
then shifting in the read silicon ID operation code followed by three
dummy bytes on ASDI. The serial configuration device’s 8-bit silicon ID
is then shifted out on the DATApin on the falling edge of DCLK, as shown
in Figure 4–12. The device can terminate the read silicon ID operation by
driving nCShigh after the silicon ID has been read at least once. Sending
additional clock cycles on DCLKwhile nCSis driven low can cause the
silicon ID to be shifted out repeatedly.
4–18
Core Version a.b.c variable
Altera Corporation
July 2004
Configuration Handbook, Volume 2
ALTERA [ ALTERA CORPORATION ]
