OM11077 NXP Semiconductors, OM11077 Datasheet - Page 372

• Manufacturer Part Number: OM11077
• Description: MODULE DIMM LPC2478 ARM7
• Manufacturer: NXP Semiconductors

Specifications of OM11077

• Accessory Type: Module Card
• For Use With/related Products: ARM-57TS-LPC2478
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-4742

NXP Semiconductors
12. USB device controller initialization
UM10237_4
User manual
Internally, there is a hardware FIFO status flag called Buffer_Full. This flag is set by the
Validate Buffer command and cleared when the data has been sent on the USB bus and
the buffer is empty.
A control IN buffer cannot be validated when its corresponding OUT buffer has the Packet
Over-written (PO) bit (see the Clear Buffer Register) set or contains a pending SETUP
packet. For the control endpoint the validated buffer will be invalidated when a SETUP
packet is received.
See
used.
The LPC2400 USB device controller initialization includes the following steps:
1. Enable the device controller by setting the PCUSB bit of PCONP.
2. Configure and enable the PLL and Clock Dividers to provide 48 MHz for usbclk, and
3. Enable the device controller clocks by setting DEV_CLK_EN and AHB_CLK_EN bits
4. Select the desired USB port pins using the USBPortSel register. The
5. Enable the USB pin functions by writing to the corresponding PINSEL register.
6. Disable the pull-up resistor on the V
7. Set USBEpIn and USBMaxPSize registers for EP0 and EP1, and wait until the
8. Enable endpoint interrupts (Slave mode):
9. Configure the DMA (DMA mode):
the desired frequency for cclk. For correct operation of synchronization logic in the
device controller, the minimum cclk frequency is 18 MHz. For the procedure for
determining the PLL setting and configuration, see
determining PLL
in the USBClkCtrl register. Poll the respective clock bits in the USBClkSt register until
they are set.
PORTSEL_CLK_EN bit must be set in USBClkCtrl before accessing USBPortSel and
should be cleared after accessing USBPortSel.
register.
EP_RLZED bit in USBDevIntSt is set so that EP0 and EP1 are realized.
– Clear all endpoint interrupts using USBEpIntClr.
– Clear any device interrupts using USBDevIntClr.
– Enable Slave mode for the desired endpoints by setting the corresponding bits in
– Set the priority of each enabled interrupt using USBEpIntPri.
– Configure the desired interrupt mode using the SIE Set Mode command.
– Enable device interrupts using USBDevIntEn (normally DEV_STAT, EP_SLOW,
– Disable DMA operation for all endpoints using USBEpDMADis.
– Clear any pending DMA requests using USBDMARClr.
Section 13–13 “Slave mode operation”
USBEpIntEn.
and possibly EP_FAST).
settings”.
Rev. 04 — 26 August 2009
BUS
Chapter 13: LPC24XX USB device controller
for a description of when this command is
pin using the corresponding PINMODE
Section 4–3.2.12 “Procedure for
UM10237
© NXP B.V. 2009. All rights reserved.
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