Universal Serial Bus (USB)
Am186™CC/CH/CU Microcontrollers User’s Manual
18-7
■
Each USB data endpoint can only be connected to a single specific SmartDMA channel,
but can be connected to any general-purpose DMA channel. Because SmartDMA
channels are directional (either transmit or receive), a general-purpose DMA channel
must be used if more than 2 IN data endpoints or more than 2 OUT data endpoints are
desired.
For more about DMA and other I/O options, see “Handling USB Data” on page 18-18.
18.4
REGISTERS
The registers listed in Table 18-3 program the USB peripheral controller. There are four
general configuration registers, six miscellaneous control and status registers, ten registers
for the dedicated control and interrupt endpoints, and eight registers each for the four data
endpoints.
Appendix A summarizes the bits in all the registers. For a complete description of all the
peripheral registers, see the
Am186™CC/CH/CU Microcontrollers Register Set Manual,
order #21916.
Table 18-3
USB Register Summary
Offset
Register
Mnemonic
Register Name
Description
USB General Configuration Registers
1E0h
UISTAT1
USB Interrupt Status 1
Common status register for interrupt-capable
status bits of each USB endpoint.
1E2h
UIMASK1
USB Interrupt Mask 1
Enables or disables interrupts generated by
UISTAT1 bits.
1E4h
UISTAT2
USB Interrupt Status 2
Shows status of USB and controller features.
1E6h
UIMASK2
USB Interrupt Mask 2
Enables or disables interrupts generated by
UISTAT2 status bits.
USB Miscellaneous Registers
1E8h
USBMFR
USB Device Miscellaneous Functions
Provides internal USB transceiver power and
disable control; USB suspend status; USB soft
reset control; USB self-powered device
attribute; and remote wake-up control/status.
1EAh
RTFMCNT
Real Time Frame Monitor Count
Used to estimate progress of the current host
frame.
1ECh
TSTMP
Time Stamp
Contains the current frame number.
1EEh
TSTMPM
Time Stamp Match
Match register for time stamp bit in UISTAT2.
1F0h
ISCTL
Isochronous Synchronization Control
Used to control external frame synchronization
(USBSOF signal enable), auto-rate bytes per
sample, USB sample source clock; and
FPMCNT bit latch count rate.
1F2h
FPMCNT
Frame Position Monitor Count
Used during isochronous IN transfers to
compare the source data rate (USBSCI signal)
to the USB host’s data rate. The host’s SOF
rate or data rate can then be adjusted
accordingly.
In the Am186CC microcontroller, the
HDLC A/PCM/GCI source data rate can also
be compared to the USB host’s data rate.
CC
CH
Содержание Am186 CC
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Страница 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...