ep2sgx60e Altera Corporation, ep2sgx60e Datasheet - Page 28

• Manufacturer Part Number: ep2sgx60e
• Description: 4. Serial Configuration Devices Epcs1, Epcs4, Epcs16, Epcs64, And Epcs128 Data Sheet
• Manufacturer: Altera Corporation

Serial Configuration Device Memory Access
Figure 4–11. Read Bytes Operation Timing Diagram
Notes to
(1)
(2)
4–28
Configuration Handbook, Volume 2
DCLK
ASDI
DATA
nCS
Address bit A[23] is a don't-care bit in EPCS64. Address bits A[23..21] are don't-care bits in EPCS16. Address
bits A[23..19] are don't-care bits in EPCS4. Address bits A[23..17] are don't-care bits in the EPCS1.
For RPD files, the read sequence shifts out the LSB of the data byte first.
Figure
0
4–11:
High Impedance
1
2
Operation Code
3
4
DCLK. The maximum DCLK frequency during the read bytes operation is
20 MHz.
operation.
The first byte address can be at any location. The device automatically
increments the address to the next higher address after shifting out each
byte of data. Therefore, the device can read the whole memory with a
single read bytes operation. When the device reaches the highest address,
the address counter restarts at 0x000000, allowing the memory contents
to be read out indefinitely until the read bytes operation is terminated by
driving nCS high. The device can drive nCS high any time after data is
shifted out. If the read bytes operation is shifted in while a write or erase
cycle is in progress, the operation is not executed and has no effect on the
write or erase cycle in progress.
Read Silicon ID Operation
The read silicon ID operation code is b'1010 1011, with the MSB listed
first. Only EPCS1, EPCS4, EPCS16, and EPCS64 support this operation. It
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
is ignored and has no effect on the cycle that is in progress.
5
6
7
Figure 4–11
MSB
23
8
22
9
21
10
24-Bit Address (1)
shows the timing diagram for the read bytes
3
28
2
29
1
30
0
31
MSB (2)
7
32
6
33
5
34
DATA Out 1
4
35
3
36
Altera Corporation
2
37
1
38
0
May 2008
39
DATA Out 2
7