Self Configuration Mode (Hm = $5): - Motorola DSP56305 User Manual

6.5.1.13.4 Enhanced Universal Bus Mode (HM = $3):
The HI32 supports:
• Slave-only glueless connection to various external buses (e.g. ISA/EISA,
DSP56300 core based DSP Port A bus).
• 24-, 16- (with data alignment), and 8-bit buses.
• ISA/EISA bus DMA-type accesses.
• Output of two control signals (data direction and data output enable) to an
optional external data buffer.
• Host select acknowledge output.
• HP19, HP31 and HP32 are unused and must be forced or pulled up to Vcc.
• When operating with a host bus less than 24 bits wide, the data signals that are
not used for transferring data must be forced or pulled up or down to Vcc or to
GND respectively. For example: when operating with a 16-bit bus (e.g. ISA bus),
HP48-HP41 must be forced or pulled up to Vcc or pulled down to GND.
6.5.1.13.5 GPIO Mode (HM = $4):
The HI32 supports:
• General purpose I/O (GPIO) port.
• Pins HP23-HP0 are GPIO.
• Pins HP48-HP33, HP30-24 are disconnected.
• HP31 and HP32 are unused and must be forced or pulled up to Vcc.
• Minimum current consumption.
6.5.1.13.6

Self Configuration Mode (HM = $5):

The HI32 supports:
• Indirect DSP56300 core access to the CCMR, CLAT and CBMA HI32
configuration registers.
• All the host port signals are in the disconnected state.
The value of the HM bits may be changed to a non zero value by the DSP56300 core only
when the HI32 is in the personal software reset state (HM = $0, HACT = 0), they must
not be changed together (i.e. in the same core write) with any of the following bits:
HDSM, HRWP, HTAP, HDRP, HRSP, HIRH, or HIRD.
The combinations HM = $6, HM = $7 are reserved for future expansion and should not
be used.
Hardware and software resets clear the HM bits.
MOTOROLA DSP56305 User's Manual
HOST INTERFACE (HI32)
DSP SIDE Programming Model
6-19