ISP1362
Single-chip USB OTG controller
Philips Semiconductors
2. Set the corresponding bits of the OtgInterruptEnable register (bits 0 to 8, or some
of them).
3. Set bit OTG_IRQ_InterruptEnable of the HcµPInterruptEnable register (bit 9).
4. Set bit InterruptPinEnable of the HcHardwareConfiguration register (bit 0).
When an interrupt is generated on INT1, perform these steps in the interrupt service
routine to get the related OTG status:
1. Read the HcµPInterrupt register. If OTG_IRQ (bit 9) is set, then step 2.
2. Read the OtgInterrupt register. If any of the bits 0 to 4 are set, then step 3.
3. Read the OtgStatus register.
The OTG state machine routines are called when any of the inputs is changed. These
inputs come from either OTG registers (hardware) or application program (software).
The outputs of the state machine include control signals to the OTG register (for
hardware) and states or error codes (for software). For more information, refer to the
Philips document ISP136x Embedded Programming Guide.
11.5 Power saving in the idle state and during wake-up
The ISP1362 can be put in the power saving mode if the OTG device is not in a
session. This significantly reduces the power consumption. In this mode, both the DC
and the HC are suspended. The PLL and the oscillator are stopped, and the charge
pump is in the suspend state.
As an OTG device, however, the ISP1362 is required to respond to the SRP event. To
support this, a LazyClock is kept running when the chip is in the power saving mode.
An SRP event will wake up the chip (that is, enable the PLL and the oscillator).
Besides this, an ID change or B_SESS_VLD detection can also wake up the chip.
These wake-up events can be enabled or disabled by programming the related bits of
the OtgInterruptEnable register before putting the chip in the power saving mode. If
the bit is set, then the corresponding event (status change) will wake up the ISP1362.
If the bit is cleared, then the corresponding event will not wake up the ISP1362.
You can also wake up the ISP1362 from the power saving mode by using software.
This is accomplished by accessing any of ISP1362 registers. Accessing a register will
assert CS of the ISP1362, and therefore, set it awake.
11.6 Current capacity of the OTG charge pump
The ISP1362 uses a built-in charge pump to generate a 5 V VBUS supply from a
3.3 V ± 0.3 V voltage source. The only external component required is a capacitor.
The value of this capacitor depends on the amount of current drive required. Table 7
provides two recommended capacitor values and the corresponding current drive.
Table 7:
Recommended capacitor values
Capacitance
27 nF
VCC
Current
8 mA
3.0 V to 3.6 V
3.0 V to 3.3 V
3.3 V to 3.6 V
82 nF
14 mA
20 mA
9397 750 12337
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Product data
Rev. 03 — 06 January 2004
38 of 150
NXP [ NXP ]
