12-34
MCF5272 User’s Manual
Software Architecture and Application Notes
5. Repeat steps 2–4 until entire packet is received.
6. Wait for EOP or SOF interrupt and read any remaining data in the FIFO.
7. An EOT interrupt indicates a short or zero-length packet.
12.4.5 Class- and Vendor-Specific Request Operation
The class- and vendor-specific requests are specific to a particular device class or vendor,
and are not processed by the USB request processor. When the USB module receives a class
or vendor request, the parameters for the request are written to the DRR1 and DRR2
registers and the user is notified of the request with the VEND_REQ interrupt. The user
must take the following step to process a class or vendor request:
1. Read DRR1 and DRR2 to determine the request type.
2. If the request has a data stage, the EP0 FIFO should be read or written with the
number of bytes as defined in the DRR2[wLength]. Refer to for more details on
accessing the FIFOs.
3. When the user has finished processing the request, EP0CTL[CMD_OVER] must be
set to signal completion of the request. [CMD_ERR] must also be set
simultaneously if an error was encountered while processing the request.
12.4.6
REMOTE
WAKEUP
and
RESUME
Operation
The MCF5272 supports USB
RESUME
initiated from three different sources. Two of the
sources are for remote wakeup capability. The three different resume mechanisms are listed
below:
•
The user sets EP0CTL[RESUME]. The USB module responds to this only if the
USB is in the suspended state and EP0SR[WAKE_ST] is set. The ColdFire core
must be running to write E0PCTL. To meet USB timing specifications, the
RESUME bit must not be set until two milliseconds have elapsed since the USB
module entered suspend state.
•
The wake-on-ring INT1 interrupt pin is at the active level defined in EP0CTL. The
USB module responds to the INT1 pin only if the wake-on-ring function is enabled,
the USB is in the suspended state and EP0SR[WAKE_ST] is set. The ColdFire core
may be powered down, and the resume signaling wakes up the ColdFire core. The
wake-on-ring function must not be enabled until two milliseconds have elapsed
since the USB module entered the suspend state in order to meet USB specification
timing requirements.
•
The USB module detects any activity on the USB, which may be normal bus activity,
resume signaling, or reset signaling. The ColdFire core may be powered down, and
the resume signaling wakes up the ColdFire core.
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
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Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...