SL811HS

Document 38-08008 Rev. *F

Page 9 of 32

USB-A/USB-B Host Transfer Count Register (Read), USB Address (Write) [Address = 04h, 0Ch]. This register has two

different functions depending on whether it is read or written. When read, this register contains the number of bytes remaining (from

Host Base Length value) after a packet is transferred. For example, if the Base Length register is set to 0x040 and an IN Token was

sent to the peripheral device. If, after the transfer is complete, the value of the Host Transfer Count is 0x10, the number of bytes

actually transferred is 0x30. This is considered as an underflow indication.

When written, this register contains the USB Device Address with which the Host communicates.

DA6-DA0

Device address, up to 127 devices can be addressed.

DA7

Reserved bit must be set to zero.

SL811HS Control Registers

The next set of registers are the Control registers and control more of the operation of the chip instead of USB packet type of transfers.

Table 10 is a summary of the control registers.

Table 8. USB-A / USB-B Host Transfer Count Register when READ [Address 04h, 0Ch]

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

HTC7

HTC6

HTC5

HTC4

HTC3

HTC2

HTC1

HTC0

Table 9. USB-A / USB-B USB Address when WRITTEN [Address 04h, 0Ch]

Bit 7

Bit 6

Bit 5

Bit 4

Bit3

Bit 2

Bit 1

Bit 0

0

DA6

DA5

DA4

DA3

DA2

DA1

DA0

Table 10. Control Registers Summary

Register Name SL811H

SL811HS (hex) Address

Control Register 1

05h

Interrupt Enable Register

06h

Reserved Register

07h

Status Register

0Dh

SOF Counter LOW (Write)/HW Revision Register (Read)

0Eh

SOF Counter HIGH and Control Register 2

0Fh

Memory Buffer

10h-FFh

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