NXP Semiconductors freescale K51 Series Reference Manual

• Updates the STATUS register to reflect the error with SEQ_RES = 00. (See Table44-18 for field values.)• Sets the CONTROL[IF] bit.• Generates an interrupt if enabled (the CONTROL[IE] bit is set).Note that in this case the module does not wait for the TVDPSRC_CON interval to elapse.At this point, control has been passed to system software via the interrupt. The rest of thesequence (detecting the type of charging port) is not applicable, so software should:1. Read the STATUS register.2. Set the CONTROL[IACK] bit to acknowledge the interrupt.3. Set the CONTROL[SR] bit to issue a software reset to the module.4. Disable the module.44.5.1.5 Charger Type DetectionAfter software enables the D+ pullup resistor, the module is notified automatically (viainternal signaling; the module waits until the ipp_pue_pullup_dp input goes high) to startthe CHECK_DM timer counting down the time interval programmed into theTIMER2[CHECK_DM] field.Once the CHECK_DM time has elapsed, the module samples the USB D- line todetermine the type of charger. See the following table.Table 44-17. Sampling D- in the Charger Type Detection PhaseIf the voltage on D- is... Then... See...High The port is a dedicated charging port.1 DedicatedCharging PortLow The port is a charging host port.2 Charging HostPort1. In a dedicated charger, the D+ and D- lines are shorted together through a small resistor.2. In a charging host port, the D+ and D- lines are not shorted.44.5.1.5.1 Dedicated Charging PortFor a dedicated charger, the module does the following:Functional DescriptionK51 Sub-Family Reference Manual, Rev. 6, Nov 20111112 Freescale Semiconductor, Inc.