cx28500 Mindspeed Technologies, cx28500 Datasheet - Page 67

• Manufacturer Part Number: cx28500
• Description: Cx28500 Multichannel Synchronous Communications Controller
• Manufacturer: Mindspeed Technologies

Figure 4-2.
4.1
4.1.1
After reset and after the PCI configuration is completed, CX28500 provides the Host the ability to read and write
peripheral devices located on the EBUS (refer to
to instruct CX28500 to perform specific EBUS operations. CX28500 can perform bulk service request commands.
The Service Request Acknowledge (SACK) can be generated either after each service request command or at the
end of each bulk service request, depending on the value of SACKIEN bit field set in the service request
configuration descriptor. (See
contains the address of the first entry in the HSDT (or refer to
Host can configure local devices connected to the EBUS by issuing the EBUS Access Service Request
(EBUS_WR or EBUS_RD). The command is a three dword memory location that contains the following dword-
fields:
•
•
•
28500-DSH-002-C
Access Control Field
Shared Memory Pointer (Buffer Address) representing the starting address of the buffer location where the
device structure resides
EBUS Base Address Offset (the address of the first EBUS transaction)
EBUS Functional Block Diagram without Local MPU
EBUS—Operational Mode
Initialization
Address/Data
Clock
Table
4-2.) CX28500 processes an SRQ by reading the HSRP register which
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Interface
EBUS
Table
4-1). The Host Service Request mechanism allows the Host
Bus Arbitration
Address/Data
Control
Clock
Section
®
Expansion
7.1.2.2). Once configured and enabled, the
Local
Bus
Downloadable
Peripheral
Local RAM
Devices
ROM
Expansion Bus (EBUS)
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