cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 97

• Manufacturer Part Number: cx28560
• Description: Hdlc Controller
• Manufacturer: Mindspeed Technologies

CX28560 Data Sheet
Table 5-5. Service Request Descriptor—OPCODE Description
28560-DSH-001-B
NOP
CONFIG_WR
CONFIG_RD
CH_ACT
CH_DEACT
RSVD
EBUS_WR
EBUS_RD
RSVD
Command
0h
1h
2h
3h
4h
5h
6h
7h
8h–1Fh
Value
No Operation.
This service request performs no action other than to facilitate a host Service Acknowledge Interrupt
(SACK). This would be used as a UNIX ping-like operation to detect the presence of the CX28560.
Configuration Write.
This is a request to copy from shared memory data into the CX28560’s internal registers. This service
request can be issued for one or more consecutive registers, depending on the value of LENGTH bit
field set in Service Request Descriptor. Note: The Service Request Descriptor used for this command is
Device Configuration Descriptor. The LENGTH bit value in this descriptor is up to 16 K. Assuming that
the host configures an 16 K register structure in shared memory and the LENGTH bit field will be set
accordingly. Note that over the PCI the configuration will be in bursts of 32 dwords (i.e., the maximum
allowed PCI burst).
Configuration Read.
This is a request to copy the configuration of the CX28560’s internal register(s) into shared memory.
The configuration located at the address specified by the CX28560 register Map Base Address Offset is
read and copied to the address specified by the shared memory address. The number of Dwords copied
is specified in the LENGTH bit field. The user needs to instruct the CX28560 to perform the correct
number of reads so that when data is written in shared memory, no data overlapping occurs. The
Service Request Descriptor used for this command is Device Configuration Descriptor.
Channel Activation.
This is a request to activate a single channel. The CX28560 assumes that the channel was already
configured. If the channel is currently active, this command results in a destructive termination of the
current message being processed, as well as flushing any other messages residing in the channel’s
FIFO. The Service Request Descriptor used for this command is Channel Configuration Descriptor.
Channel Deactivation.
This is a request to deactivate a channel. This command results in a destructive termination of the
current message being processed, as well as flushing of any other messages residing in the channel’s
FIFO. The SRD used for this command is Channel Configuration Descriptor.
Reserved.
EBUS Write.
This is a request to execute write transaction(s) over the EBUS. Data is copied from host memory to the
EBUS.
EBUS Read.
This is a request to execute read transaction(s) over the EBUS. Data is copied from the EBUS Address
specified in the 3rd dword of EBUS Configuration Descriptor to the shared memory location specified in
the 2nd dword of EBUS Configuration Descriptor. The data length copied from one location to another
location is specified by LENGTH bit field in EBUS Configuration Descriptor. Note: The EBUS_RD and
EBUS_WR Service Request mechanism allow a maximum of 16 K dwords transfer to/from the EBUS. The
transaction is split to bursts of 32 dwords over the PCI.
Reserved.
A similar situation arises when performing a change of Flexiframe. The SACK
interrupt (if enabled) will be returned once the new Flexiframe has been read into the
CX28560’s internal memory. However the system can only assume that the actual
move to use the new Flexiframe has been made once the RNFFRAME or
TNFFRAME bit (see
NFFRAMEI interrupt has been received.
Mindspeed Technologies™
Advance Information
Table 5-29
or
Table
Description
5-44) has been set to zero or the
The CX28560 Memory Organization
5
-
7