C8051T322-GQR Silicon Labs, C8051T322-GQR Datasheet - Page 166

• 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
23.6. Function Addressing
The FADDR register holds the current USB0 function address. Software should write the host-assigned 7-
bit function address to the FADDR register when received as part of a SET_ADDRESS command. A new
address written to FADDR will not take effect (USB0 will not respond to the new address) until the end of
the current transfer (typically following the status phase of the SET_ADDRESS command transfer). The
UPDATE bit (FADDR.7) is set to 1 by hardware when software writes a new address to the FADDR regis-
ter. Hardware clears the UPDATE bit when the new address takes effect as described above.
USB Register Definition 23.7. FADDR: USB0 Function Address
USB Register Address = 0x00
23.7. Function Configuration and Control
The USB register POWER (USB Register Definition 23.8) is used to configure and control USB0 at the
device level (enable/disable, Reset/Suspend/Resume handling, etc.).
USB Reset: The USBRST bit (POWER.3) is set to 1 by hardware when Reset signaling is detected on the
bus. Upon this detection, the following occur:
1. The USB0 Address is reset (FADDR = 0x00).
2. Endpoint FIFOs are flushed.
3. Control/status registers are reset to 0x00 (E0CSR, EINCSRL, EINCSRH, EOUTCSRL, EOUTCSRH).
4. USB register INDEX is reset to 0x00.
5. All USB interrupts (excluding the Suspend interrupt) are enabled and their corresponding flags cleared.
6. A USB Reset interrupt is generated if enabled.
Writing a 1 to the USBRST bit will generate an asynchronous USB0 reset. All USB registers are reset to
their default values following this asynchronous reset.
Suspend Mode: With Suspend Detection enabled (SUSEN = 1), USB0 will enter Suspend Mode when
Suspend signaling is detected on the bus. An interrupt will be generated if enabled (SUSINTE = 1). The
Suspend Interrupt Service Routine (ISR) should perform application-specific configuration tasks such as
166
Name
Reset
6:0 FADDR[6:0] Function Address Bits.
Bit
Type
7
Bit
UPDATE
Name
UPDATE
R
7
0
Function Address Update Bit.
Set to 1 when software writes the FADDR register. USB0 clears this bit to 0 when the
new address takes effect.
0: The last address written to FADDR is in effect.
1: The last address written to FADDR is not yet in effect.
Holds the 7-bit function address for USB0. This address should be written by software
when the SET_ADDRESS standard device request is received on Endpoint0. The
new address takes effect when the device request completes.
6
0
5
0
Rev. 1.1
4
0
FADDR[6:0]
Function
R/W
3
0
2
0
1
0
0
0