
30
USB 2.0 (USB20SR) Device IP Core User Guide
System Level Solutions
January 2013
Core Registers
25:24
RW
TR_TYPE
Transfer Type
This two bits are used to configure the endpoint for different types of transfer support on
it. USB controller handles transaction over the endpoint differently depending on this
input.
00: Interrupt
01: Isochronous
10: Bulk
11: Reserved
23:22
RW
EP_DIS
Temporarily Disable EP
These two bits are used to control the endpoint during error condition. Halt feature of the
endpoint is set to send stall handshake to the host controller. Endpoint can be disabled
temporary through these bits for avoiding any process by controller over the endpoint.
00: Normal
01: Force the core to ignore transfer over this EP
10: Set EP HALT
11: Reserved
21:18
RO
EP_number
17
RW
LRG_OK
These bits are used to show the number. Endpoint numbers are fixed from hardware
itself and it can not be changed through software.
1 - Accept data packets of more than MAX_PL_SZ (RX only)
0 - Ignore data packets of more than MAX_PL_SZ (RX only)
16
RW
Small_ok
This bit is used by device to check whether endpoint is configured for receiving packet
with payload size less then max packet length. If this bit is set to 1, then device will
accept the received packet with payload less then the maximum packet length size set-
ting of the endpoint. If this bit is set to 0 then endpoint will receive only those packet from
host which has data payload size as its maximum packet length size. Device will discard
all small packets received from host on its own and no information will be provided to
host.
15
RO
Reserved
14
RO
Reserved
13
RO
Reserved