AT85C51SND3Bx
Bit
Bit
Number
Mnemonic Description
Pipe Data Bits
7-0
PDAT7:0
Set by the software to read/write a byte from/to the Pipe FIFO selected by
PNUM.
Reset Value = 0000 0000b
Table 151. UPBCHX Register
UPBCHX (1.D4h) – USB Pipe Data Counter High Register
7
6
5
4
3
2
1
0
-
-
-
-
-
PBYCT10
PBYCT9
PBYCT8
Bit
Bit
Number
Mnemonic Description
Reserved
7-3
2-0
-
The value read from these bits is always 0. Do not set these bits.
Byte count (high) Bits
PBYCT10:8
Set by hardware. This field is the MSB of the byte count of the FIFO endpoint.
The LSB part is provided by the UPBCLX register.
Reset Value = 0000 0000b
Table 152. UPBCLX Register
UPBCLX (1.D5h) – USB Pipe Data Counter Low Register
7
6
5
4
3
2
1
0
PBYCT7
PBYCT6
PBYCT5
PBYCT4
PBYCT3
PBYCT2
PBYCT1
PBYCT0
Bit
Bit
Number
Mnemonic Description
Byte Count (low) Bits
Set by the hardware. PBYCT10:0 is:
- (for OUT Pipe) increased after each writing into the Pipe and decremented after
each byte sent,
7-0
PBYCT7:0
- (for IN Pipe) increased after each byte received by the host, and decremented
after each byte read by the software.
Reset Value = 0000 0000b
147
7632A–MP3–03/06
ATMEL [ ATMEL ]
