Cypress EZ-USB FX3 User Manual

EZ-USB FX3 Technical Reference Manual, Document Number: 001-76074 Rev. *F 611
SCK_STATUS
0x0C
10.25.4 SCK_STATUS (continued)
17:15 STATE[2:0] Internal operating state of the socket. This field is used for debugging and to safely modify active
sockets (see go_suspend).
10 AVL_ENABLE Enables the functioning of AVL_COUNT and AVL_MIN. When 0, it will disable both stalling on
AVL_MIN and generation of the sck_more_buf_avl signal described above.
9:5 AVL_MIN Minimum number of available buffers required by the adapter before activating a new one. This can
be used to guarantee a minimum number of buffers available with old data to implement rollback. If
AVL_ENABLE, the socket will remain in STALL state until AVL_COUNT>=AVL_MIN.
4:0 AVL_COUNT Number of available (free for ingress, occupied for egress) descriptors beyond the current one. This
number is incremented by the adapter whenever an event is received on this socket and decre-
mented whenever it activates a new descriptor. This value is used to create a signal to the IP Cores
that indicates at least one buffer is available beyond the current one (sck_more_buf_avl).
State
Default Description
DESCR 9 Descriptor state. This is the default initial state indicating the descriptor registers are NOT valid in the
Adapter. The Adapter will start loading the descriptor from memory if the socket becomes enabled and not
suspended. Suspend has no effect on any other state.
STALL 1 Stall state. Socket is stalled waiting for data to be loaded into the Fetch Queue or waiting for an event.
ACTIVE 2 Active state. Socket is available for core data transfers.
EVENT 3 Event state. Core transfer is done. Descriptor is being written back to memory and an event is being
generated if enabled.
CHECK1 4 Check states. An active socket gets here based on the core’s EOP request to check the Transfer size and
determine whether the buffer should be wrapped up. Depending on result, socket will either go back to
Active state or move to the Event state.
SUSPENDED 5 Socket is suspended
CHECK2 6 Check states. An active socket gets here based on the core’s EOP request to check the Transfer size and
determine whether the buffer should be wrapped up. Depending on result, socket will either go back to
Active state or move to the Event state.
WAITING 7 Waiting for confirmation that event was sent.

Cypress EZ-USB FX3 Specifications

General

Brand	Cypress
Model	EZ-USB FX3
Category	Controller
Language	English