Figure 6-7 Single Strobe Bus - Motorola DSP56309 User Manual

6.5.6.11 HPCR Host Address Strobe Polarity (HASP) Bit 10
If HASP is cleared, the host address strobe (HAS) signal is an active low input, and the
address on the host address/data bus is sampled when the HAS signal is low. If HASP is
set, HAS is an active high address strobe input, and the address on the host address or
data bus is sampled when the HAS signal is high.
6.5.6.12 HPCR Host Multiplexed Bus (HMUX) Bit 11
If HMUX is set, the HI08 latches the lower portion of a multiplexed address/data bus. In
this mode the internal address line values of the host registers are taken from the
internal latch. If HMUX is cleared, it indicates that the HI08 is connected to a
non-multiplexed type of bus. The values of the address lines are then taken from the
HI08 input signals.
6.5.6.13 HPCR Host Dual Data Strobe (HDDS) Bit 12
If the HDDS bit is cleared, the HI08 operates in the single-strobe bus mode. In this mode,
the bus has a single data strobe signal for both reads and writes. If set, the HI08 operates
in the dual-strobe bus mode. In this mode, the bus has two separate data strobes, one for
data reads, the other for data writes. See Figure 6-7 and Figure 6-8 for more information
on the two types of buses.
HRW
HDS
In a single-strobe bus, a DS (data strobe) signal qualifies the access, while a R/W (Read-Write)
signal specifies the direction of the access.
MOTOROLA
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Figure 6-7 Single Strobe Bus

DSP56309UM/D
Host Interface (HI08)
HI08 DSP Side ProgrammerÕs Model
AA0661
6-15