
Rev. 1.1 (April 2012)
9
DLP Design, Inc.
Command Packets
Command
Packet
Description
Byte
Hex
Value
Return/Comments
Ping
Issues Ping
0
0x00
Ping Command - 0x56 will be returned indicating that
the DLP-HS-FPGA3 is found on the selected port.
Read
Version/
Status
Accesses
the internal
version/
status
registers
0
0x10
Read Version/Status Registers Command
1
0xnn
Register Address: 0xnn =
0x00 = Board ID (0x30 = Production PCB)
0x01 = FPGA Type ID : 0x6A = XC3S1400A
0x02 = Design Version ID 1 (Design Month)
0x03 = Design Version ID 2 (Design Day)
0x04 = Design Version ID 3 (Design Year)
0x05 = Design Version ID 4 (Design Version)
0x06 = DDR2 Status: 0x00 = Not Initialized
0x01 = Initialized
Loopback
Returns the
data byte
received
0
0x20
Loopback Command
1
0xnn
The byte sent to the DLP-HS-FPGA3 (0xnn) will be
returned back.
Loopback
Compliment
Returns the
compliment
of data byte
received
0
0x21
Loopback Compliment Command
1
0xnn
The byte sent to the DLP-HS-FPGA3 (0xnn) will be
complimented and returned back.
Read Pin
Reads the
state of one
of the user
I/O pins
0
0x30
Read Pin Command
1
0x00
–
0x3E
The user I/O pin numbers are described in Table 2.
User I/O pin 0xnn is read and returns:
0x00 = User I/O pin 0xnn is low
0x01 = User I/O pin 0xnn is high
Clear Pin
Forces the
selected
user I/O pin
low
0
0x40
Clear Pin Command
1
0x00
–
0x3E
The user I/O pin numbers are described in Table 2.
User I/O pin 0xnn is cleared. The specified user I/O
number is returned.
Set Pin
Forces the
selected
user I/O pin
high
0
0x41
Set Pin Command
1
0x00
–
0x3E
The user I/O pin numbers are described in Table 2.
User I/O pin 0xnn is set. The specified user I/O number
is returned.
Initialize
Memory
Initializes
DDR2
SDRAM
0
0x70
The Initialize Memory Command configures the DDR2
SDRAM for access by the FPGA. The memory cannot
be accessed without being initialized.
IMPORTANT NOTE ON DDR2 SDRAM DATA ACCESS:
Writes and reads made to and from the DDR2 SDRAM using the reference design on the
DLP-HS-FPGA3 module are always performed 4 bytes at a time due to the fact that the device is
configured for a burst length of four. What this means is that Column Address Bits 0 and 1 only
change the order of the read or write bytes; they still refer to the same 4 bytes. Therefore, to
increment the DDR2 SDRAM address for consecutive memory locations, the column address must be
incremented by 4.
Incrementing the column address by anything less than 4 simply changes the order in which the 4
bytes specified by Column Address 9:3 are written to the memory or returned to the user.