SL811HS
5.2.4
SOF Packet Generation
The SL811HS automatically computes CRC5 by hardware. No CRC or SOF is required to be generated by external firmware for
SL811HS.
5.2.5
USB-A/USB-B Host Base Address [01H, 09H]
The USB-A/USB-B Base Address is a Pointer to the SL811HS memory buffer location for USB reads and writes. When trans-
ferring data OUT (Host to Device), the USB-A and USB-B can be set up prior to setting ARM on the USB-A or USB-B Host Control
register. See the software implementation example.
5.2.6
USB-A/USB-B Host Base Length [02H, 0AH]
The USB A/B host base register contains the maximum packet size to be transferred between the SL811HS and a slave USB
peripheral. Essentially, this designates the largest packet size that can be transferred by the SL811HS. Base Length designates
the size of data packet to be sent. For example, in Bulk mode the maximum packet length is 64 bytes. In ISO mode, the maximum
packet length is 1023, since the SL811HS only has an 8-bit length; the maximum packet size for the ISO mode using the SL811HS
is 255 – 16 bytes. When the Host Base Length register is set to zero, a Zero-Length packet will be transferred.
5.2.7
USB-A/USB-B Host PID, Device Endpoint (Write)/USB Status (Read) [03H, 0BH]
This register has two modes. When read, this register provides packet status and it contains information relative to the last packet
that has been received or transmitted. The register is defined as follows.
Bit Position
Bit Name
ACK
Function
0
1
2
3
4
5
6
7
Transmission Acknowledge
Error detected in transmission
Time-out occurred
Error
Time-out
Sequence
Setup
Sequence Bit. “0” if DATA0, “1” if DATA1
“1” indicates Setup Packet
Overflow
NAK
Overflow condition - maximum length exceeded during receives
Slave returns NAK
STALL
Slave set STALL bit
When written, this register provides the PID and Endpoint information to the USB SIE engine to be used in the next transaction.
All sixteen Endpoints can be addressed by the SL811HS.
D7
D6
D5
D4
D3
D2
D1
D0
PID3
PID2
PID1
PID0
EP3
EP2
EP1
EP0
PID3-0
EP3-0
4-bit PID Field (See Table Below)
4-bit Endpoint Value in Binary.
PID TYPE
D7-D4
SETUP
IN
1101 (D Hex)
1001 (9 Hex)
OUT
0001 (1 Hex)
0101 (5 Hex)
1100 (C Hex)
1010 (A Hex)
1110 (E Hex)
0011 (3 Hex)
1011 (B Hex)
SOF
PREAMBLE
NAK
STALL
DATA0
DATA1
Document #: 38-08008 Rev. *A
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