IDT Programming the Device
Revision 1.5
Integrated Device Technology, Inc.
CPS-16/12/8 User Manual
8 - 9
July 10, 2012
8.2.7.5 Force Local
The CPS supports “force local” references in its Domain Route Table. A Force Local reference of 0xDD in
the Domain Route Table forces a lookup with the 8 lower (lsb) bits of the destination ID in the Device Route
Table.
8.3 DEVICE PROGRAMMING
This section provides a overview of device programming sequence and reference.
8.3.1 Power Up and Reset
There are no power-up sequencing requirements with respect to the multiple supplies on the device. There
is no power ramp up rate requirement.
With the device powered-up and the DC pins held static, it is time to issue a reset to the device. A reset is
REQUIRED prior to performing any other operations on the device. Described here are the necessary
steps. Please refer to the Reset & Initialization chapter for full detail.
There are three options to affect a hard reset of the CPS: driving the RST pin, writing to the Soft Reset
Register, or receipt of an sRIO link-request reset control symbol.
A hard reset MUST be performed after power-up. All three methods are equivalent. Each sets all internal
registers to default values, and resets all PLLs. It also resets all port configurations to default, and sets the
port speeds according the speed pins previously mentioned.
A hard reset can also be performed any time after power-up by writing to the Soft Reset Register. Writing to
the reset register can be accomplished via the I
2
C port, the JTAG port, or a host processor appropriately
configured to communicate through the default sRIO port configuration of the CPS.
The third method is performed via sRIO control symbol. RapidIO defines a Link-Request Control Symbol
that resets the receiving device. The CPS defines two options that define the behavior of the CPS when this
control symbol is received from one of the RIO ports. The user can program the ENABLE_PORT_RESET
field in CPS_CONTROL register. If this bit is set to 0, the whole device will be reset upon receipt of a reset
symbol. Otherwise it will reset the port on which the symbol was received.
8.3.2 Per Port Reset
Per Port reset is reset to a single port only which is invoked when that port receives a sequence of four link-
request or reset-device controls (also called a link-reset) as described by the sRIO spec in part-6. The
reception of a local reset to the port is referred to below as a local soft reset event and affects the port in the
following ways:
1. The input-retry state machine and input-error state machine are returned to their initial states, regard-
less of what the state was at the time the reset was received (including the stopped states).
2. The condition of actively receiving a packet is cleared on the input port, as if the packet had been
cancelled. Packet word counters for measuring packet length are cleared to zero.
3. The local soft reset event causes any current packet being received to be discarded and not
accepted by the switch.
4. Logic exists in the input port to detect when two link-requests are received before the port has trans-
mitted a link-response for the first-link request. This logic is reset by local soft reset event.
5. The status control symbol counters are reset to zero. These are the counters which track the number
of status control symbols that have been received and transmitted by the port following link bring up
for the purpose of placing the port in the normal mode (i.e.- for asserting the port_OK bit).
6. The local soft reset event causes the register to be reset which tracks the value of the ackid that is
expected in the next packet that the port receives. Thus, following the local soft reset event, the port
will be expecting the next packet that it receives to have ackid of zero.
