CY7C68013A, CY7C68014A
CY7C68015A, CY7C68016A
3.12.5 Default Full Speed Alternate Settings
Table 6. Default Full Speed Alternate Settings[4, 5]
Alternate Setting
0
64
0
1
2
3
ep0
64
64
64
ep1out
ep1in
ep2
64 bulk
64 bulk
64 int
64 int
64 int
0
64 int
0
64 bulk out (2×)
64 bulk out (2×)
64 bulk in (2×)
64 bulk in (2×)
64 int out (2×)
64 bulk out (2×)
64 int in (2×)
64 iso out (2×)
64 bulk out (2×)
64 iso in (2×)
64 bulk in (2×)
ep4
0
ep6
0
ep8
0
64 bulk in (2×)
3.12.6 Default High Speed Alternate Settings
Table 7. Default High Speed Alternate Settings[4, 5]
Alternate Setting
0
1
2
3
ep0
64
0
64
64
64
ep1out
ep1in
ep2
512 bulk[6]
512 bulk[6]
64 int
64 int
0
64 int
64 int
0
512 bulk out (2×)
512 bulk out (2×)
512 bulk in (2×)
512 bulk in (2×)
512 int out (2×)
512 bulk out (2×)
512 int in (2×)
512 bulk in (2×)
512 iso out (2×)
512 bulk out (2×)
512 iso in (2×)
512 bulk in (2×)
ep4
0
ep6
0
ep8
0
domain. The blocks can be configured as single, double, triple,
or quad buffered as previously shown.
3.13 External FIFO Interface
3.13.1 Architecture
The I/O control unit implements either an internal master (M for
master) or external master (S for Slave) interface.
The FX2LP slave FIFO architecture has eight 512 byte blocks in
the endpoint RAM that directly serve as FIFO memories and are
controlled by FIFO control signals (such as IFCLK, SLCS#,
SLRD, SLWR, SLOE, PKTEND, and flags).
In Master (M) mode, the GPIF internally controls FIFOADR[1..0]
to select a FIFO. The RDY pins (two in the 56-pin package, six
in the 100-pin and 128-pin packages) can be used as flag inputs
from an external FIFO or other logic if desired. The GPIF can be
run from either an internally derived clock or externally supplied
clock (IFCLK), at a rate that transfers data up to 96 Megabytes/s
(48 MHz IFCLK with 16-bit interface).
In operation, some of the eight RAM blocks fill or empty from the
SIE, while the others are connected to the I/O transfer logic. The
transfer logic takes two forms, the GPIF for internally generated
control signals and the slave FIFO interface for externally
controlled transfers.
In Slave (S) mode, the FX2LP accepts either an internally
derived clock or externally supplied clock (IFCLK, max frequency
48 MHz) and SLCS#, SLRD, SLWR, SLOE, PKTEND signals
from external logic. When using an external IFCLK, the external
clock must be present before switching to the external clock with
the IFCLKSRC bit. Each endpoint can individually be selected
for byte or word operation by an internal configuration bit and a
Slave FIFO Output Enable signal SLOE enables data of the
selected width. External logic must ensure that the output enable
signal is inactive when writing data to a slave FIFO. The slave
interface can also operate asynchronously, where the SLRD and
SLWR signals act directly as strobes, rather than a clock qualifier
as in synchronous mode. The signals SLRD, SLWR, SLOE and
PKTEND are gated by the signal SLCS#.
3.13.2 Master/Slave Control Signals
The FX2LP endpoint FIFOS are implemented as eight physically
distinct 256x16 RAM blocks. The 8051/SIE can switch any of the
RAM blocks between two domains, the USB (SIE) domain and
the 8051-I/O Unit domain. This switching is done virtually
instantaneously, giving essentially zero transfer time between
“USB FIFOS” and “Slave FIFOS.” Because they are physically
the same memory no bytes are actually transferred between
buffers.
At any time, some RAM blocks are filling/emptying with USB data
under SIE control, while other RAM blocks are available to the
8051, the I/O control unit or both. The RAM blocks operate as
single port in the USB domain, and dual port in the 8051-I/O
Notes
4. “0” means “not implemented.”
5. “2×” means “double buffered.”
6. Even though these buffers are 64 bytes, they are reported as 512 for USB 2.0 compliance. The user must never transfer packets larger than 64 bytes to EP1.
Document #: 38-08032 Rev. *N
Page 11 of 62
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