Atmel Xplained Pro Evaluation Kit for the ATSAMD21J18A Microcontroller ATSAMD21-XPRO ATSAMD21-XPRO Data Sheet
Product codes
ATSAMD21-XPRO
771
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181C–SAM-D21_Datasheet–07/2014
31.8.2.4 Device Frame Number
Name:
FNUM
Offset:
0x10
Reset:
0x0000
Property:
Read only
z
Bit 15 – FNCERR: Frame Number CRC Error
This bit is cleared upon receiving a USB reset.
This bit is set when a corrupted frame number (or micro-frame number) is received.
This bit and the SOF (or MSOF) interrupt bit are updated at the same time.
This bit is cleared upon receiving a USB reset.
This bit is set when a corrupted frame number (or micro-frame number) is received.
This bit and the SOF (or MSOF) interrupt bit are updated at the same time.
z
Bit 14 – Reserved
This bit is unused and reserved for future use. For compatibility with future devices, always write this bit to zero
when this register is written. This bit will always return zero when read.
This bit is unused and reserved for future use. For compatibility with future devices, always write this bit to zero
when this register is written. This bit will always return zero when read.
z
Bits 13:3 – FNUM: Frame Number
These bits are cleared upon receiving a USB reset.
These bits are updated with the frame number information as provided from the last SOF packet even if a cor-
rupted SOF is received.
These bits are cleared upon receiving a USB reset.
These bits are updated with the frame number information as provided from the last SOF packet even if a cor-
rupted SOF is received.
z
Bits 2:0 – MFNUM: Micro Frame Number
These bits are cleared upon receiving a USB reset or at the beginning of each Start-of-Frame (SOF interrupt).
These bits are updated with the micro-frame number information as provided from the last MSOF packet even if a
corrupted MSOF is received.
These bits are cleared upon receiving a USB reset or at the beginning of each Start-of-Frame (SOF interrupt).
These bits are updated with the micro-frame number information as provided from the last MSOF packet even if a
corrupted MSOF is received.
Bit
15
14
13
12
11
10
9
8
FNCERR
FNUM[10:5]
Access
R
R
R
R
R
R
R
R
Reset
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
FNUM[4:0]
MFNUM[2:0]
Access
R
R
R
R
R
R
R
R
Reset
0
0
0
0
0
0
0
0