at89c5131 ATMEL Corporation, at89c5131 Datasheet - Page 147

• Manufacturer Part Number: at89c5131
• Description: 8-bit Flash Microcontroller With Full Speed Usb Device At89c5131
• Manufacturer: ATMEL Corporation

4136C–USB–04/05
Table 103. UFNUMH Register
UFNUMH (S:BBh, read-only)
USB Frame Number High Register
Reset Value = 00h
Table 104. UFNUML Register
UFNUML (S:BAh, read-only)
USB Frame Number Low Register
Reset Value = 00h
Bit Number
Number
FNUM7
Bit
2-0
7 - 0
5
4
3
7
7
-
Mnemonic
FNUM[10:8]
Mnemonic Description
CRCERR
FNUM[7:0]
CRCOK
FNUM6
Bit
Bit
-
6
6
-
Description
Frame Number CRC OK
This bit is set by hardware when a new Frame Number in Start of Frame Packet
is received without CRC error.
This bit is updated after every Start of Frame packet receipt.
Important note: the Start of Frame interrupt is generated just after the PID receipt.
Frame Number CRC Error
This bit is set by hardware when a corrupted Frame Number in Start of Frame
packet is received.
This bit is updated after every Start of Frame packet receipt.
Important note: the Start of Frame interrupt is generated just after the PID receipt.
Reserved
The value read from this bit is always 0. Do not set this bit.
Frame Number
FNUM[10:8] are the upper 3 bits of the 11-bit Frame Number (see the “UFNUML
Register UFNUML (S:BAh, read-only) USB Frame Number Low Register” on
page 145). It is provided in the last received SOF packet (see SOFINT in the
“USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on
page 136). FNUM is updated if a corrupted SOF is received.
Frame Number
FNUM[7:0] are the lower 8 bits of the 11-bit Frame Number (See “UFNUMH
Register UFNUMH (S:BBh, read-only) USB Frame Number High Register” on
page 145).
CRCOK
FNUM5
5
5
CRCERR
FNUM4
4
4
FNUM3
3
3
-
FNUM10
FNUM2
2
2
AT89C5131
FNUM9
FNUM1
1
1
FNUM8
FNUM0
0
0
145