MCF548x Reference Manual, Rev. 3
29-28 Freescale Semiconductor

29.2.4.2 Endpoint n Max Packet Size Register (EP0MPSR, EPnOUTMPSR,

EPnINMPSR)

The endpoint max packet size registers contain the maximum packet size that this endpoint, in its current
configuration, is capable of transmitting or receiving.
These registers should be updated by the USB application before enabling the USB device for the first time
and again following a configuration change (i.e. upon the reception of a SET_CONFIGURATION or
SET_INTERFACE request). The value programmed into this register should correspond with the
wMaxPacketSize field of the associated endpoint descriptor (see section 9.6.6 of the USB Specification,
Rev. 2.0).
76543210
R000000 TTYPE
W
Reset000000Uninitialized
Reg
Addr
MBAR + 0xB149 (EP1NACR); 0xB179 (EP2NACR); 0xB1A9 (EP3INACR);
0xB1D9 (EP4INACR); 0xB209 (EP5INACR); 0xB239 (EP6INACR)
Figure 29-27. Endpoint n Attribute Control Register IN (EPnINACR)
Table 29-26. EPnOUTACR and EPnINACR Field Descriptions
Bits Name Description
7–2 Reserved, should be cleared.
1–0 TTYPE Transfer type. Indicates the type of transfers that will be used for the designated endpoint.
00 Control (This value is always used for EP0 and is not valid for any other endpoint)
01 Isochronous
10 Bulk
11 Interrupt
1514131211109876543210
R 0 0 0 ADDTRANS MAXPKTSZ
W
Reset0000000000000000
Reg
Addr
MBAR + 0xB102 (EP0OUTPSR); 0xB132 (EP1OUTPSR); 0xB162 (EP2OUTPSR); 0xB192 (EP3OUTPSR);
0xB1C2 (EP4OUTPSR); 0xB1F2 (EP5OUTPSR); 0xB222 (EP6OUTPSR)
Figure 29-28. Endpoint n Max Packet Size Register OUT (EPnOUTMPSR)