at85c51snd3b ATMEL Corporation, at85c51snd3b Datasheet - Page 184

• Manufacturer Part Number: at85c51snd3b
• Description: Single-chip Digital Audio Decoder - Encoder With Usb 2.0 Interface
• Manufacturer: ATMEL Corporation

Card Lock Input
Interrupt Unit
184
AT85C51SND3B
As shown in Figure 83 the SMLCK (SMC/XD Lock) input implements an internal pull-up,
in order to provide static high level when card is not present in the socket.
SMLCK level is reported by SMLCK bit
Note:
Figure 83. Card Write Protection Input Block Diagram
As shown in Figure 84, the NF controller implements five interrupt sources reported in
SMCTI, ILGLI, ECCRDYI, ECCERRI, STOPI flags in NFINT register. These flags must
be cleared by software when processing the interrupt service routine.
All these sources are enabled separately using SMCTE, ILGLE, ECCRDYE,
ECCERRE, STOPE enable bits respectively in NFIEN register.
The interrupt request is generated each time an enabled flag is set, and the global NFC
controller interrupt enable bit is set (ENFC in IEN1 register).
Figure 84. NFC Controller Interrupt System
There are 2 kinds of interrupts: processing (i.e. their generation is part of the normal pro-
cessing) and exception (i.e. their generation correspond to error cases).
Processing interrupts are generated when:
•
•
•
Exception Interrupts are generated when the following events are met:
•
ECCRDYI
ECCERRI
running to not running state transition (STOPI)
ECC ready for operation (ECCRDYI)
SMC insertion or removal (SMCTI)
ECC error (ECCERRI)
SMCTI
NFINT.4
NFINT.3
NFINT.2
NFINT.1
STOPI
NFINT.0
ILGLI
1. SDWP bit is not relevant until SMC management is enabled and a card is present in
the socket (SMCD = 0).
ECCRDYE
STOPE
NFIEN.0
SMCTE
NFIEN.4
NFIEN.2
SMLCK
ECCERRI
NFIEN.3
NFIEN.1
ILGLE
(1)
IOVDD
in NFSTA register.
R
PU
SMLCK
NFSTA.6
ENFC
IEN1.4
NFC Controller
Interrupt Request
7632C–MP3–11/06