Cypress SL811HS - Manual (Page 6)

SL811HS
Document 38-08008 Rev. *D Page 6 of 32
USB-A/USB-B Host Base Length [Address = 02h, 0Ah].
The USB A/B Host Base Length register contains the maximum packet size transferred between the SL811HS and a slave USB
peripheral. Essentially, this designates the largest packet size that is transferred by the SL811HS. Base Length designates the
size of data packet sent or received. For example, in full speed BULK mode, the maximum packet length is 64 bytes. In ISO
mode, the maximum packet length is 1023 bytes since the SL811HS only has an 8-bit length; the maximum packet size for the
ISO mode using the SL811HS is 255 – 16 bytes (register space). When the Host Base length register is set to zero, a Zero-Length
packet is transmitted.
USB-A/USB-B USB Packet Status (Read) and Host PID, Device Endpoint (Write) [Address = 03h, 0Bh]. This register has
two modes dependent on whether it is read or written. When read, this register provides packet status and contains information
relative to the last packet that has been received or transmitted. This register is not valid for reading until after the Done interrupt
occurs, which causes the register to update.
When written, this register provides the PID and Endpoint information to the USB SIE engine used in the next transaction. All 16
Endpoints can be addressed by the SL811HS.
PID[3:0]: 4-bit PID Field (See Table Below), EP[3:0]: 4-bit Endpoint Value in Binary.
Table 5. USB-A / USB-B Host Base Length Definition [Address 02h, 0Ah]
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
HBL7 HBL6 HBL5 HBL4 HBL3 HBL2 HBL1 HBL0
Table 6. USB-A/USB-B USB Packet Status Register Definition when READ [Address 03h, 0Bh]
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
STALL NAK Overflow Setup Sequence Time-out Error ACK
Bit Position Bit Name Function
7 STALL Slave device returned a STALL.
6 NAK Slave device returned a NAK.
5 Overflow Overflow condition - maximum length exceeded during receives. For underflow, see
USB-A/USB-B Host Transfer Count Register (Read), USB Address (Write) [Address = 04h,
0Ch] on page 7
.
4 Setup This bit is not applicable for Host operation since a SETUP packet is generated by the host.
3 Sequence Sequence bit. ’0’ if DATA0, ’1’ if DATA1.
2 Time-out Timeout occurred. A timeout is defined as 18-bit times without a device response (in full
speed).
1 Error Error detected in transmission. This includes CRC5, CRC16, and PID errors.
0 ACK Transmission Acknowledge.
Table 7. USB-A / USB-B Host PID and Device Endpoint Register when WRITTEN [Address 03h, 0Bh]
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
PID3 PID2 PID1 PID0 EP3 EP2 EP1 EP0
PID TYPE D7-D4
SETUP 1101 (D Hex)
IN 1001 (9 Hex)
OUT 0001 (1 Hex)
SOF 0101 (5 Hex)
PREAMBLE 1100 (C Hex)
NAK 1010 (A Hex)
STALL 1110 (E Hex)
DATA0 0011 (3 Hex)
DATA1 1011 (B Hex)