Universal Serial Bus (USB)
18-32
Am186™CC/CH/CU Microcontrollers User’s Manual
18.5.12.3
Data Endpoint Definition
The Am186CC and Am186CU microcontrollers each provide four general-purpose data
endpoints. These endpoints transfer large amounts of data between the USB host and
device using either the USB bulk, isochronous, or interrupt transfer protocols. Note that if
the data endpoint is programmed for interrupt transfer, the DMA mode is not applicable.
Typically, all of the USB Device Class specifications require that a USB device contain any
number and type of data endpoints to transfer the various data types required by the device
class.
The data endpoint features are highly programmable. Device software can modify these
features at any time in response to the various commands issued to the device’s control
endpoint. Table 18-9 lists the data endpoint features.
Table 18-9
Data Endpoints A–D Definition
Parameter
Values
USB Parameters
Number
1–15
Configuration
0–3
Interface
0–3
Alternate Setting
0–7
Direction
(Endpoints A and C)
IN or OUT
OUT
Direction
(Endpoints B and D)
IN
Type
Interrupt,
Bulk, or
Isochronous
Bulk
Isochronous
Bulk
Isochronous
Max. Packet Size
(Endpoints A and B)
1–16 bytes
(8 or 16 for
bulk)
8, 16, 32, or
64 bytes
1–1023
bytes
1
Notes:
1. A 24-MHz processor clock is not fast enough for software to keep up with 1023-byte isochronous
IN or OUT packets using only an 8, 16, or 32-byte FIFO. If a 24-MHz processor clock is used and a
Max Packet Size of 1023 bytes is required for isochronous data, use endpoint C or D and set the
FIFO size to 64 bytes.
8, 16, 32, or
64 bytes
1–1023
bytes
1
Max. Packet Size
(Endpoints C and D)
1–64 bytes
(8 16, 32, or
64 for bulk)
8, 16, 32, or
64 bytes
1–1023
bytes
8, 16, 32, or
64 bytes
1–1023
bytes
System Parameters
Data Handling
Polled I/O
or Interrupt
Driven
General-Purpose DMA
SmartDMA Channel
FIFO Depth
(Endpoints A and B)
8 or 16 bytes
FIFO Depth
(Endpoints C and D)
8, 16, 32, or 64 bytes
Summary of Contents for Am186 CC
Page 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Page 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Page 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Page 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Page 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Page 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Page 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Page 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Page 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...