Nxp Semiconductors UM10237 用户手册

UM10237_2

© NXP B.V. 2008. All rights reserved.

USBReEp |= (UInt32) ((0x1 << endpt));

/* Load Endpoint index Reg with physical endpoint no.*/

USBEpIn = (UInt32) endpointnumber;

/* load the max packet size Register */

USBEpMaxPSize = MPS;

/* check whether the EP_RLZED bit in the Device Interrupt Status register is set 

*/

while (!(USBDevIntSt & EP_RLZED))

{

/* wait until endpoint realization is complete */

}

/* Clear the EP_RLZED bit */

Clear EP_RLZED bit in USBDevIntSt;

}

The device will not respond to any transactions to unrealized endpoints. The SIE 
Configure Device command will only cause realized and enabled endpoints to respond to 
transactions. For details see 

.

Each endpoint has a register carrying the MaxPacketSize value for that endpoint. This is 
in fact a register array. Hence before writing, this register is addressed through the 
USBEpIn register. 

The USBEpIn register will hold the physical endpoint number. Writing to USBMaxPSize 
will set the array element pointed to by USBEpIn. USBEpIn is a write only register.

 

On reset, the control endpoint is assigned the maximum packet size of 8 bytes. Other 
endpoints are assigned 0. Modifying USBMaxPSize will cause the endpoint buffer 
addresses within the EP_RAM to be recalculated. This is a multi-cycle process. At the 
end, the EP_RLZED bit will be set in USBDevIntSt (

). USBMaxPSize array 

indexing is shown in 

. USBMaxPSize is a read/write register.

 

[1]

Reset value for EP0 and EP1. All other endpoints have a reset value of 0x0.

4:0

PHY_EP

Physical endpoint number (0-31)

0

31:5

-

Reserved, user software should not write ones to reserved 
bits. The value read from a reserved bit is not defined.

NA

9:0

MPS

The maximum packet size value.

31:10

-

Reserved, user software should not write ones to reserved 
bits. The value read from a reserved bit is not defined.

NA