CY7C68013A/CY7C68014A
CY7C68015A/CY7C68016A
3.12.5 Default Full-Speed Alternate Settings
[4, 5]
Table 3-6. Default Full-Speed Alternate Settings
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
64 int
0
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×)
ep4
0
ep6
0
ep8
0
64 bulk in (2×)
64 bulk in (2×)
3.12.6 Default High-Speed Alternate Settings
[4, 5]
Table 3-7. Default High-Speed Alternate Settings
Alternate Setting
0
1
2
3
ep0
64
0
64
64
64
[6]
[6]
ep1out
ep1in
ep2
512 bulk
512 bulk
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
port in the 8051-I/O 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, or 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 insure 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 physi-
cally 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.” Since they are
physically the same memory, no bytes are actually transferred
between buffers.
At any given time, some RAM blocks are filling/emptying with
USB data under SIE control, while other RAM blocks are
available to the 8051 and/or the I/O control unit. The RAM
blocks operate as single-port in the USB domain, and dual-
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. *G
Page 11 of 55
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