USBx_OTGCTL field descriptions (continued)
Field
Description
3
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
2
OTGEN
On-The-Go pullup/pulldown resistor enable
0
If USB_EN is 1 and HOST_MODE is 0 in the Control Register (CTL), then the D+ Data Line pull-up
resistors are enabled. If HOST_MODE is 1 the D+ and D– Data Line pull-down resistors are engaged.
1
The pull-up and pull-down controls in this register are used.
1–0
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
42.4.9 Interrupt Status register (USBx_ISTAT)
Contains fields for each of the interrupt sources within the USB Module. Each of these
fields are qualified with their respective interrupt enable bits. All fields of this register are
logically OR'd together along with the OTG Interrupt Status Register (OTGSTAT) to
form a single interrupt source for the processor's interrupt controller. After an interrupt
bit has been set it may only be cleared by writing a one to the respective interrupt bit.
This register contains the value of 0x00 after a reset.
Address: 4007_2000h base + 80h offset = 4007_2080h
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
0
0
0
0
0
0
0
0
USBx_ISTAT field descriptions
Field
Description
7
STALL
Stall Interrupt
In Target mode this bit is asserted when a STALL handshake is sent by the SIE.
In Host mode this bit is set when the USB Module detects a STALL acknowledge during the handshake
phase of a USB transaction.This interrupt can be used to determine whether the last USB transaction was
completed successfully or stalled.
6
ATTACH
Attach Interrupt
This field is set when the USB Module detects an attach of a USB device. This field is only valid if
CTL[HOSTMODEEN]=1. This interrupt signifies that a peripheral is now present and must be configured; it
is asserted if there have been no transitions on the USB for 2.5 µs and the current bus state is not SE0."
0
No Attach is detected since the last time the ATTACH bit was cleared.
1
A peripheral is now present and must be configured (a stable non-SE0 state is detected for more than
2.5 µs).
Table continues on the next page...
Chapter 42 Universal Serial Bus Full Speed OTG Controller (USBFSOTG)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc.
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