Bit
Bit
Number
Mnemonic Description
Busy Bank Flag
Set by hardware to indicate the number of busy bank.
For IN endpoint, it indicates the number of busy bank(s), filled by the user, ready
for IN transfer.
NBUSYBK1:
0
For OUT endpoint, it indicates the number of busy bank(s) filled by OUT
1-0
transaction from the host.
00b: All banks are free
01b: 1 busy bank
10b: 2 busy banks
11b: Reserved.
Reset Value = 0000 0000b
Table 125. UESTA1X Register
UESTA1X (1.CFh) – USB Endpoint Status 1 Register
7
6
5
4
3
2
1
0
-
-
-
-
-
CTRLDIR
CURRBK1 CURRBK0
Bit
Bit
Number
Mnemonic Description
Reserved
7-3
-
The value read from these bits is always 0. Do not set these bits.
Control Direction (Flag, and bit for debug purpose)
Set by hardware after a SETUP packet, and gives the direction of the following
packet:
- 1 for IN endpoint
2
CTRLDIR
- 0 for OUT endpoint.
Can not be set or cleared by software.
Current Bank (all endpoints except Control endpoint) Flag
Set by hardware to indicate the number of the current bank:
00b: Bank0
01b: Bank1
1-0
CURRBK1:0
1xb: Reserved.
Can not be set or cleared by software.
Reset Value = 0000 0000b
122
AT85C51SND3Bx
7632A–MP3–03/06
ATMEL [ ATMEL ]
