ATMEGA16U2-16AU Atmel, ATMEGA16U2-16AU Datasheet - Page 213

• Manufacturer Part Number: ATMEGA16U2-16AU
• Description: 8-bit Microcontrollers - MCU 16K Flash
• Manufacturer: Atmel

Specifications of ATMEGA16U2-16AU

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: AVR
• Data Bus Width: 8 bit
• Program Memory Size: 16 KB
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Program Memory Type: Flash
• Factory Pack Quantity: 1250

21.18.5
21.18.6
21.18.7
7799D–AVR–11/10
UDFNUMH – USB Device Frame Number High Register
UDFNUML – USB Device Frame Number Low Register
UDMFN – USB Device Micro Frame Number
• Bits 7:3 – Res: Reserved
These bits are reserved and will always read as zero.
• Bits 2:0 – FNUM[10:8]: Frame Number Upper Flag
These bits are read-only and updated by the hardware USB controller. These bits contains the 3
MSB of the 11-bits Frame Number information. The content of these bits is updated with the last
received SOF packet. These bits are updated even if a corrupted SOF has been received. When
a corrupted SOF number is detected, the FNCERR bit of UDMFN is set.
• Bits 7:0 – FNUM: Frame Number Lower Flag
These bits are read-only and updated by the hardware USB controller. These bits contains the 8
LSB of the 11-bits Frame Number information. The content of these bits is updated with the last
received SOF packet. These bits are updated even if a corrupted SOF has been received. When
a corrupted SOF number is detected, the FNCERR bit of UDMFN is set.
• Bit 7:5 – Res: Reserved
These bits are reserved and will always read as zero.
• Bit 4 – FNCERR: Frame Number CRC Error Flag
This bit is set by the USB controller when a corrupted frame number in Start of frame packet is
received. When an incorrect frame number is detected both SOFI flag and this bit are set.
• Bits 3:0 – Res: Reserved
These bits are reserved and will always read as zero.
Bit
(0xE5)
Read/Write
Initial Value
Bit
(0xE4)
Read/Write
Initial Value
Bit
(0xE6)
Read/Write
Initial Value
R
7
0
-
R
7
0
R
7
0
-
R
6
0
-
R
R
6
0
6
0
-
R
R
5
0
5
0
-
R
5
0
-
FNCERR
R/W
R
4
0
-
R
4
0
4
0
FNUM[7:0]
ATmega8U2/16U2/32U2
R
3
0
R
R
-
3
0
3
0
-
R
2
0
R
R
2
0
2
0
-
FNUM[10:8]
1
R
0
R
R
1
0
1
0
-
R
R
R
0
0
0
0
0
0
-
UDFNUMH
UDFNUML
UDMFN
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