AT43USB355M-AC ATMEL [ATMEL Corporation], AT43USB355M-AC Datasheet - Page 85

• Manufacturer Part Number: AT43USB355M-AC
• Description: Full-speed USB Microcontroller with Embedded Hub, ADC and PWM
• Manufacturer: ATMEL [ATMEL Corporation]

2603G–USB–04/06
Hub End-point 0 Byte Count Register – HBYTE_CNT0
Function End-point 0..3 Byte Count Register – FBYTE_CNT0..3
The contents of these registers stores the number of bytes to be sent or that was received by
USB Hub and Function end-points. This count includes the 16-bit CRC. To get the actual byte
count of the data, subtract the count in the register by 2. The hub EP0 and function EP3 have
8 byte FIFOs while function EP1 and EP2 have 64 byte FIFOs. Hub end-point 1 has no byte
count register.
• Bit 7..6 – Reserved
These bits are reserved in the AT43USB355 and will read as zero.
• Bit 5..0 – BYTCT5..0: Byte Count – Length of End-point Data Packet
Function EP0 $1FCD
Function EP1 $1FCC
Function EP2 $1FCB
Function EP3 $1FCA
Hub EP0 $1FCF
Read/Write
Initial Value
Bit
R
7
–
–
–
–
–
0
BYTCT6
BYTCT6
R
6
–
–
–
0
BYTCT5
BYTCT5
BYTCT5
BYTCT5
BYTCT5
R
5
0
BYTCT4
BYTCT4
BYTCT4
BYTCT4
BYTCT4
R/W
4
0
BYTCT3
BYTCT3
BYTCT3
BYTCT3
BYTCT3
R/W
3
0
BYTCT2
BYTCT2
BYTCT2
BYTCT2
BYTCT2
R/W
2
0
BYTCT1
BYTCT1
BYTCT1
BYTCT1
BYTCT1
R/W
AT43USB355
1
0
BYTCT0
BYTCT0
BYTCT0
BYTCT0
BYTCT0
R/W
0
0
HBYTE_CNT0
FBYTE_CNT0
FBYTE_CNT1
FBYTE_CNT2
FBYTE_CNT3
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