CCS C Compiler Manual PCB / PCM / PCH

Functional Overview
USB
Universal Serial Bus, or USB, is used as a method for peripheral devices to connect to and talk
to a personal computer. CCS provides libraries for interfacing a PIC to PC using USB by using
a PIC with an internal USB peripheral (like the PIC16C765 or the PIC18F4550 family) or by
using any PIC with an external USB peripheral (the National USBN9603 family).
Relevant Functions:
usb_init()
usb_init_cs()
usb_task()
Initializes the USB hardware. Will then wait in an infinite loop for the
USB peripheral to be connected to bus (but that doesn't mean it has
been enumerated by the PC). Will enable and use the USB interrupt.
The same as usb_init(), but does not wait for the device to be
connected to the bus. This is useful if your device is not bus powered
and can operate without a USB connection.
If you use connection sense, and the usb_init_cs() for initialization, then
you must periodically call this function to keep an eye on the connection
sense pin. When the PIC is connected to the BUS, this function will then
perpare the USB peripheral. When the PIC is disconnected from the
BUS, it will reset the USB stack and peripheral. Will enable and use the
USB interrupt.
Note: In your application you must define USB_CON_SENSE_PIN to the connection sense pin.
usb_detach()
usb_attach()
usb_attached()
usb_enumerated()
Removes the PIC from the bus. Will be called automatically by
usb_task() if connection is lost, but can be called manually by the user.
Attaches the PIC to the bus. Will be called automatically by usb_task()
if connection is made, but can be called manually by the user.
If using connection sense pin (USB_CON_SENSE_PIN), returns TRUE
if that pin is high. Else will always return TRUE.
Returns TRUE if the device has been enumerated by the PC. If the
device has been enumerated by the PC, that means it is in normal
operation mode and you can send/receive packets.
usb_put_packet Places the packet of data into the specified endpoint buffer. Returns
(endpoint, data, len, tgl) TRUE if success, FALSE if the buffer is still full with the last packet.
usb_puts
(endpoint, data, len,
timeout)
Sends the following data to the specified endpoint. usb_puts() differs
from usb_put_packet() in that it will send multi packet messages if the
data will not fit into one packet.
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