
Registers
985
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Host Port Interface (HPI)
Table 21-14. Host Port Interface Control Register (HPIC) Field Descriptions
Bit
Field
Value
Description
31-12
Reserved
0
Reserved
11
HPIASEL
HPI address register select bit. When DUALHPIA = 1, the HPIASEL bit is used to select the HPI
address register to be accessed.
0
Selects the HPI write address register (HPIAW).
1
Selects the HPI read address register (HPIAR).
10
Reserved
0
Reserved. Always write 0 to this bit.
9
DUALHPIA
Dual HPIA mode configuration bit. The CPU can access both HPI address registers separately,
regardless of the DUALHPIA setting. (Regardless of this bit, dual HPIA mode is implied when the
CPU has ownership of the HPI address registers).
0
The two HPI address registers (HPIAW and HPIAR) operate as a single HPI address register in
terms of host accesses.
1
Dual HPIA mode operation is enabled.
8
HWOBSTAT
HWOB status. The value of the HWOB bit is also stored in this bit position. A write to the HWOB bit
also updates HWOBSTAT.
0
HWOB bit is logic 0.
1
HWOB bit is logic 1.
7
HPIRST
HPI reset. Some HPI logic is held in reset when the HPIRST bit is set. The HPIRST bit must be
cleared to 0 before data transactions can take place.
0
HPI is released from reset.
1
HPI is held in reset.
6-5
Reserved
2h
Reserved
4
FETCH
Host data fetch request bit. Only the host may write to FETCH. When a host writes a 1 to FETCH, a
request is posted in the HPI to prefetch data into the read FIFO. Host and CPU reads of FETCH
return a 0.
3
Reserved
1
Reserved
2
HINT
Processor-to-host interrupt. The CPU writes a 1 to HINT to generate a host interrupt. HINT has an
inverted logic level to the UHPI_HINT pin. The host must write a 1 to HINT to clear the UHPI_HINT
pin; writing a 0 to HINT by the host or processor has no effect.
0
No effect.
1
A CPU write generates a host interrupt (UHPI_HINT signal goes low). A host write sets the
UHPI_HINT signal high (clears the interrupt).
1
DSPINT
Host-to-processor interrupt. The host writes a 1 to DSPINT to generate a processor interrupt;
writing a 0 to DSPINT by the host or processor has no effect.
0
No effect.
1
A host write generates a processor interrupt.
0
HWOB
Halfword ordering bit. HWOB affects both data and address transfers. HWOB must be initialized
before the first data or address register access.
0
First halfword is most significant.
1
First halfword is least significant.