SL811HS
Document 38-08008 Rev. *D Page 5 of 32
USB-A/USB-B Host Control Registers [Address = 00h, 08h] .
Once the other SL811HS Control registers are configured (registers 01h-04h or 09h-0Ch) the Host Control register is programmed
to initiate the USB transfer. This register initiates the transfer when the Enable and Arm bit are set as described above.
USB-A/USB-B Host Base Address [Address = 01h, 09h] .
The USB-A/B Base Address is a pointer to the SL811HS memory buffer location for USB reads and writes. When transferring
data OUT (Host to Device), the USB-A and USB-B Host Base Address registers can be set up before setting ARM on the USB-A
or USB-B Host Control register. When using a double buffer scheme, the Host Base Address could be set up with the first buffer
used for DATA0 data and the other for DATA1 data.
Table 3. USB-A/USB-B Host Control Register Definition [Address 00h, 08h]
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Preamble Data Toggle Bit SyncSOF ISO Reserved Direction Enable Arm
Bit Position Bit Name Function
7 Preamble If bit = ’1’ a preamble token is transmitted before transfer of low speed packet. If bit =’0’,
preamble generation is disabled.
• The SL811HS automatically generates preamble packets when bit 7 is set. This bit is only
used to send packets to a low speed device through a hub. To communicate to a full
speed device, this bit is set to ‘0’. For example, when SL811HS communicates to a low
speed device via the HUB:
— Set SL811HS SIE to operate at full speed, i.e., bit 5 of register 05h (Control Register 1)
= ’0’.
— Set bit 6 of register 0Fh (Control Register 2) = ’0’. Set correct polarity of DATA+ and
DATA– state for full speed.
— Set bit 7, Preamble bit, = ’1’ in the Host Control register.
• When SL811HS communicates directly to a low speed device:
— Set bit 5 of register 05h (Control Register 1) = ’1’.
— Set bit 6 of register 0Fh (Control Register 2) = ’1’, DATA+ and DATA– polarity for low
speed.
— The state of bit 7 is ignored in this mode.
6 Data Toggle Bit ’0’ if DATA0, ’1’ if DATA1 (only used for OUT tokens in host mode).
5 SyncSOF ’1’ = Synchronize with the SOF transfer when operating in FS only.
The SL811HS uses bit 5 to enable transfer of a data packet after a SOF packet is transmitted.
When bit 5 = ‘1’, the next enabled packet is sent after next SOF. If bit 5 = ‘0’ the next packet
is sent immediately if the SIE is free. If operating in low speed, do not set this bit.
4 ISO When set to ’1’, this bit allows Isochronous mode for this packet.
3 Reserved Bit 3 is reserved for future use.
2 Direction When equal to ’1’ transmit (OUT). When equal to ’0’ receive (IN).
1 Enable If Enable = ’1’, this bit allows transfers to occur. If Enable = ’0’, USB transactions are ignored.
The Enable bit is used in conjunction with the Arm bit (bit 0 of this register) for USB transfers.
0 Arm Allows enabled transfers when Arm = ’1’. Cleared to ’0’ when transfer is complete (when
Done Interrupt is asserted).
Table 4. USB-A/USB-B Host Base Address Definition [Address 01h, 09h]
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
HBADD7 HBADD6 HBADD5 HBADD4 HBADD3 HBADD2 HBADD1 HBADD0