Register Descriptions
1352
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Universal Serial Bus (USB) Controller
18.5.9 USB Frame Value Register (USBFRAME), offset 0x00C
The frame number 16-bit read-only register (USBFRAME) holds the last received frame number.
Mode(s):
OTG A or Host
OTG B or Device
USBFRAME is shown in
and described in
Figure 18-13. Frame Number Register (FRAME)
15
11
10
0
Reserved
FRAME
R-0
R-0
LEGEND: R = Read only; -
n
= value after reset
Table 18-16. Frame Number Register (FRAME) Field Descriptions
Bit
Field
Value
Description
15-11
Reserved
0
Reserved
10-0
FRAME
0-7FFh
Last received frame number
18.5.10 USB Endpoint Index Register (USBEPIDX), offset 0x00E
Each endpoint's buffer can be accessed by configuring a FIFO size and starting address. The endpoint
index 16-bit register (USBEPIDX) is used with the USBTXFIFOSZ, USBRXFIFOSZ, USBTXFIFOADD,
and USBRXFIFOADD registers.
Mode(s):
OTG A or Host
OTG B or Device
USBEPIDX is shown in
and described in
Figure 18-14. USB Endpoint Index Register (USBEPIDX)
7
4
3
0
Reserved
EPIDX
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 18-17. USB Endpoint Index Register (USBEPIDX) Field Descriptions
Bit
Field
Value
Description
7-4
Reserved
0
Reserved
3-0
EPIDX
0-4h
Endpoint Index. This bit field configures which endpoint is accessed when reading or writing to one of
the USB controller's indexed registers. A value of 0x0 corresponds to Endpoint 0 and a value of 0xF
corresponds to Endpoint 15.