Information

USBDCD_STATUS field descriptions (continued)
Field Description
19–18
SEQ_STAT
Charger Detection Sequence Status
Indicates the status of the charger detection sequence.
00 The module is either not enabled, or the module is enabled but the data pins have not yet been
detected.
01 Data pin contact detection is complete.
10 Charging port detection is complete.
11 Charger type detection is complete.
17–16
SEQ_RES
Charger Detection Sequence Results
Reports how the charger detection is attached.
00 No results to report.
01 Attached to a standard host. Must comply with USB 2.0 by drawing only 2.5 mA (max) until
connected.
10 Attached to a charging port. The exact meaning depends on bit 18:
• 0: Attached to either a charging host or a dedicated charger. The charger type detection has
not completed.
• 1: Attached to a charging host. The charger type detection has completed.
11 Attached to a dedicated charger.
15–0
Reserved
This field is reserved.
41.4.4 TIMER0 register (USBDCD_TIMER0)
TIMER0 has an TSEQ_INIT field that represents the system latency in ms. Latency is
measured from the time when VBUS goes active until the time system software initiates
charger detection sequence in USBDCD module. When software sets the
CONTROL[START] bit, the Unit Connection Timer (TUNITCON) is initialized with the
value of TSEQ_INIT.
Valid values are 0–1023, however the USB Battery Charging Specification requires the
entire sequence, including TSEQ_INIT, to be completed in 1s or less.
Address: USBDCD_TIMER0 is 4003_5000h base + 10h offset = 4003_5010h
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
0
TSEQ_INIT
0 TUNITCON
W
Reset
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Memory map/Register definition
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
934 Freescale Semiconductor, Inc.