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TSS901E

Rev. C – 24-Aug-01

Register Set

This chapter describes the TSS901E registers which can be read or written by the HOCI

or via the link (in case the "control by link" is enabled) to control TSS901E operations.

All TSS901E control operations are performed by writes or reads of the respective regis-

ters. Most of the control operations are obvious from the content of the registers.

General Conventions:

•

bit 0 (D0) = least significant bit,

•

bit 7 (D7) = most significant bit (or bit 15 resp. bit 31)

•

D x:0 means data bit x until bit 0.

Access by HOCI: HOCI data transfer

Big/Little endian selection of the HOCI is done using a special pin (HOSTBIGE) of the

TSS901E. By connecting this pin to either Vcc or GND the HOCI is configured to be in

little or big endian mode as follows:

When Signal HOSTBIGE = '0' (GND), the HOCI data port is in little endian mode.

When Signal HOSTBIGE = '1' (Vcc), the HOCI data port is in big endian mode.

Little endian mode selected:

•

8 bit data port (default after reset)

–

register byte 0 is connected with pin HDATA0 - HDATA7

•

16 bit data port

–

register byte 0 is connected with pin HDATA0 - HDATA7

–

register byte 1 is connected with pin HDATA8 - HDATA15

•

32 bit data port

–

register byte 0 is connected with pin HDATA0 - HDATA7

–

register byte 1 is connected with pin HDATA8 - HDATA15

–

register byte 2 is connected with pin HDATA16 - HDATA23

–

register byte 3 is connected with pin HDATA24 - HDATA31

Big endian mode selected:

•

8 bit data port (default after reset)

–

register byte 0 is connected with pin HDATA24 - HDATA31

•

16 bit data port

–

register byte 0 is connected with pin HDATA24 - HDATA31

–

register byte 1 is connected with pin HDATA16 - HDATA23

•

32 bit data port

–

register byte 0 is connected with pin HDATA24 - HDATA31

–

register byte 1 is connected with pin HDATA16 - HDATA23

–

register byte 2 is connected with pin HDATA8 - HDATA15

–

register byte 3 is connected with pin HDATA0 - HDATA7

The registers of the TSS901E are 1, 2 or 4 Bytes wide. That means, if the HOCI data

port is in 8 bit mode, 4 read or write accesses are necessary to access a 4 Byte register

(e. g. the interrupt mask register). In 16/32 bit mode the data bits 31 - 8 are '0' if an 8 bit

register is read.