DSP56KFAMUM/AD(1996) View Datasheet(PDF) - Motorola => Freescale
Part Name
Description
Manufacturer
DSP56KFAMUM/AD Datasheet PDF : 110 Pages
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Signal/Pin Descriptions
Host Interface (HI) Port
Signal
Name
HEN
PB12
HREQ
PB13
HACK
PB14
Table 1-9 HI Signals (Continued)
Signal
Type
State
during
Reset
Signal Description
Input
Tri-stated Host Enable—This input enables a data transfer on the host data
bus. When HEN is asserted and HR/W is high, H0–H7 become
outputs and the host processor may read DSP56002/L002 data.
When HEN is asserted and HR/W is low, H0–H7 become
inputs. Host data is latched inside the DSP on the rising edge of
HEN. Normally, a chip select signal derived from host address
decoding and an enable strobe are used to generate HEN.
Input
or
Output
Port B GPIO 12 (PB12)—This signal is a General Purpose I/O
signal called PB12 when the Host Interface is not being used.
After reset, the default state for this signal is GPIO input.
Open Tri-stated Host Request—This signal is used by the Host Interface to
drain
request service from the host processor, DMA controller, or a
Output
simple external controller.
Note: HREQ should always be pulled high when it is not in
use.
Input
or
Output
Port B GPIO 13 (PB13)—This signal is a General Purpose (not
open-drain) I/O signal (PB13) when the Host Interface is not
selected.
After reset, the default state for this signal is GPIO input.
Input
Tri-stated Host Acknowledge—This input has two functions. It provides a
host acknowledge handshake signal for DMA transfers and it
receives a host interrupt acknowledge compatible with MC68000
family processors.
Note: HACK should always be pulled high when it is not in
use.
Input
or
Output
Port B GPIO 14 (PB14)—This signal is a General Purpose I/O
signal (PB14) when the Host Interface is not selected.
After reset, the default state for this signal is GPIO input.
MOTOROLA
DSP56002/D, Rev. 3
1-13
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