C8051T322-GQR Silicon Labs, C8051T322-GQR Datasheet - Page 167

• Manufacturer Part Number: C8051T322-GQR
• Description: 8-bit Microcontrollers - MCU USB-OTP-16K-LQFP32
• Manufacturer: Silicon Labs

Specifications of C8051T322-GQR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

C8051T620/621/320/321/322/323
disabling appropriate peripherals and/or configuring clock sources for low power modes. See Section
“21.3. Programmable Internal High-Frequency (H-F) Oscillator” on page 125 for more details on internal
oscillator configuration, including the Suspend mode feature of the internal oscillator.
USB0 exits Suspend mode when any of the following occur: (1) Resume signaling is detected or gener-
ated, (2) Reset signaling is detected, or (3) a device or USB reset occurs. If suspended, the internal oscil-
lator will exit Suspend mode upon any of the above listed events.
Resume Signaling: USB0 will exit Suspend mode if Resume signaling is detected on the bus. A Resume
interrupt will be generated upon detection if enabled (RESINTE = 1). Software may force a Remote
Wakeup by writing 1 to the RESUME bit (POWER.2). When forcing a Remote Wakeup, software should
write RESUME = 0 to end Resume signaling 10-15 ms after the Remote Wakeup is initiated (RESUME =
1).
ISO Update: When software writes 1 to the ISOUP bit (POWER.7), the ISO Update function is enabled.
With ISO Update enabled, new packets written to an ISO IN endpoint will not be transmitted until a new
Start-Of-Frame (SOF) is received. If the ISO IN endpoint receives an IN token before a SOF, USB0 will
transmit a zero-length packet. When ISOUP = 1, ISO Update is enabled for all ISO endpoints.
USB Enable: USB0 is disabled following a Power-On-Reset (POR). USB0 is enabled by clearing the
USBINH bit (POWER.4). Once written to 0, the USBINH can only be set to 1 by one of the following: (1) a
Power-On-Reset (POR), or (2) an asynchronous USB0 reset generated by writing 1 to the USBRST bit
(POWER.3).
Software should perform all USB0 configuration before enabling USB0. The configuration sequence
should be performed as follows:
1. Select and enable the USB clock source.
2. Reset USB0 by writing USBRST= 1.
3. Configure and enable the USB Transceiver.
4. Perform any USB0 function configuration (interrupts, Suspend detect).
5. Enable USB0 by writing USBINH = 0.
Rev. 1.1
167