USB Registers
1744
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Universal Serial Bus (USB) Controller
27.5.38 USBNAKLMT Register (Offset = 0x10B) [reset = 0x0]
USB NAK Limit (USBNAKLMT)
OTG A / Host
USBNAKLMT is an 8-bit register that sets the number of frames after which endpoint 0 should time out on
receiving a stream of NAK responses. (Equivalent settings for other endpoints can be made through their
USBTXINTERVALn and USBRXINTERVALn registers.)
The number of frames selected is 2
(m-1)
(where m is the value set in the register, with valid values of 2 to
16). If the Host receives NAK responses from the target for more frames than the number represented by
the limit set in this register, the endpoint is halted.
NOTE:
A value of 0 or 1 disables the NAK time-out function.
USBNAKLMT is shown in
and described in
Return to
Figure 27-45. USBNAKLMT Register
7
6
5
4
3
2
1
0
RESERVED
NAKLMT
R-0x0
R/W-0x0
Table 27-50. USBNAKLMT Register Field Descriptions
Bit
Field
Type
Reset
Description
7-5
RESERVED
R
0x0
4-0
NAKLMT
R/W
0x0
EP0 NAK Limit.
This field specifies the number of frames after receiving a stream of
NAK responses.