usb_reset.c

cygnal 源代码

/*
   Copyright 2003 Cygnal Integrated Products, Inc.

   File:    reset.c
   Author:  JS
   Created: JAN 03

   Target Device: C8051F320

   Source file for USB firmware. Includes the USBReset and
   supporting routines. The USBReset routine should be called
   after a RESET condition is detected on the bus. The following
   are included:

   - USBReset(): Resets the device status structure, all
      endpoints (including Endpoint0), and all endpoint
      status structures.
   - EndpointReset(): Resets the status structure
      for the selected endpoint. The endpoint is left
      in the halted state

******************************************/

#include "c8051F320.h"
#include "usb_main.h"
#include "usb_desc.h"
#include "usb_config.h"
#include "usb_structs.h"
#include "usb_regs.h"

extern DEVICE_STATUS gDeviceStatus;
extern EP_STATUS gEp0Status;
extern EP_STATUS gEp1InStatus;
extern EP_STATUS gEp2OutStatus;

//---------------------------
// USBReset
//---------------------------
// - Initialize the global Device Status structure (all zeros)
// - Resets all endpoints
//
void USBReset ()
{
   BYTE i, bPower = 0;
   BYTE * pDevStatus;

  // Reset device status structure to all zeros (undefined)
   pDevStatus = (BYTE *)&gDeviceStatus;
   for (i=0;i<sizeof(DEVICE_STATUS);i++)
   {
      *pDevStatus++ = 0x00;
   }

   // Set device state to default
   gDeviceStatus.bDevState = DEV_DEFAULT;

   // REMOTE_WAKEUP_SUPPORT and SELF_POWERED_SUPPORT
   // defined in file "usb_desc.h"
   gDeviceStatus.bRemoteWakeupSupport = REMOTE_WAKEUP_SUPPORT;
   gDeviceStatus.bSelfPoweredStatus = SELF_POWERED_SUPPORT;

   // Reset all endpoints

   // Reset Endpoint0
   gEp0Status.bEpState = EP_IDLE;         // Reset Endpoint0 state
   gEp0Status.bEp = 0;                    // Set endpoint number
   gEp0Status.uMaxP = EP0_MAXP;           // Set maximum packet size

   // Reset Endpoint1 IN
   gEp1InStatus.bEpState = EP_HALTED;     // Reset state
   gEp1InStatus.uNumBytes = 0;            // Reset byte counter          

   // Reset Endpoint2 OUT
   gEp2OutStatus.bEpState = EP_HALTED;    // Reset state
   gEp2OutStatus.uNumBytes = 0;           // Reset byte counter

   // Get Suspend enable/disable status. If enabled, prepare temporary
   // variable bPower.
   if (SUSPEND_ENABLE)
   {
      bPower = 0x01;                      // Set bit0 (Suspend Enable)
   }

   // Get ISO Update enable/disable status. If enabled, prepare temporary
   // variable bPower.
   if (ISO_UPDATE_ENABLE)
   {
      bPower |= 0x80;                     // Set bit7 (ISO Update Enable)
   }

   UWRITE_BYTE(POWER, bPower);

}