EPCS4 datasheet(18/32 Pages) ALTERA

18 / 32 page

4–18

Core Version a.b.c variable

Altera Corporation

Configuration Handbook, Volume 2

July 2004

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

DATA output 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.

The device implements the read silicon ID operation by driving

nCS low

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

DATA pin on the falling edge of DCLK, as shown

in Figure 4–12. The device can terminate the read silicon ID operation by

driving

nCS high after the silicon ID has been read at least once. Sending

additional clock cycles on

DCLK while nCS is driven low can cause the

silicon ID to be shifted out repeatedly.

Table 4–11. Serial Configuration Device Silicon ID

Serial Configuration Device

Silicon ID (Binary Value)

EPCS1

b'0001 0000

EPCS4

b'0001 0010

EPCS4 Datasheet(PDF) 18 Page - Altera Corporation