Revision 1.5
Integrated Device Technology, Inc.
CPS-16/12/8 User Manual
8 - 1
July 10, 2012
Chapter 8
Programming the
Device
8 PROGRAMMING THE DEVICE
This chapter focuses on actual real-world usage of the device. This covers configuring and using the switch.
8.1 DEVICE ACCESS
The device can be programmed through three different interfaces: in-band through any of the RIO ports, or
out of band through the I
2
C & JTAG interfaces. This section provides an overview of how each of those
interfaces is used for programming. The subsequent sections provide the register and memory map which
will be the target of all programming operations on these interfaces.
8.1.1 RIO Access
The CPS device provides in-band control plane access each of its RapidIO ports through sRIO mainte-
nance packets. By sending RIO maintenance packets to the CPS, the user is capable of accessing the
device’s supported RIO registers and all other memory-mapped registers and internal memories.
In terms of Maintenance Packets, the CPS functions per the RapidIO specifications as a switch. It identifies
a Maintenance Packet by decoding the ftype field to be 0b1000. The CPS decodes the RIO defined
hop_count field of the Maintenance Packet. If it has the value of 0, the CPS terminate and process the
packet. If the hop_count field is greater than 0, the CPS decrements the value by 1, recalculate the CRC
and forward the packet to the destined port.
The CPS device supports both 8- and 16-bit destination IDs, where the size of the destination ID is defined
by the tt field. The size of the destination ID in both cases are 8 bits. The format of the RIO Maintenance
Request Packet with 8 bit addressing is as shown in the CPS destined Maintenance Packet figure shown
below. If a Maintenance Packet is received with a transaction field (ttype) different from 0b0000 or 0b0001,
then the CPS terminates the packet and logs an error.
Table 8.1 RIO Defined Maintenance Packet with CPS as Destination
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
AckID
rsvd
CR
F
Prio
tt
ftype = 0b1000
destination ID
source ID
ttype
rdsize/wrtsize
Source Transaction ID srcTID
Hop_Count
Config_Offset [20:13]
Config_Offset [12:0]
W
0b00
Data
Data......................................................................................................Data
Data
CRC