dsp56167 Freescale Semiconductor, Inc, dsp56167 Datasheet - Page 19

• Manufacturer Part Number: dsp56167
• Description: Advance Information 16-bit Digital Signal Processor
• Manufacturer: Freescale Semiconductor, Inc

MOTOROLA
HREQ
PB13
HACK
PB14
Signal
Name
Output
Output
Output
Input/
Input/
Signal
Open
Input
Type
drain
Tri-stated Host Request— This signal is used by the Host Interface to
Tri-stated Host Acknowledge— This input has two functions:
during
Reset
State
Table 1-9 HI Signals (Continued)
request service from the host processor, DMA controller, or a
simple external controller. HREQ is asserted when an enabled
request occurs in the HI. The signal is deasserted when the
request is cleared or masked, the DMA controller asserts HACK,
or the DSP is reset.
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.
Port B GPIO 14 (PB14)—This signal is a GPIO signal (PB14)
when the Host Interface is not selected.
After reset, the default state for this signal is GPIO input.
DSP56167/D, Rev. 1
1.
2.
Host Acknowledge handshake signal—HACK may be
used as a data strobe for HI DMA data transfers
MC68000 Host Interrupt Acknowledge—This function
enables the HI Interrupt Vector Register (IVR) onto the
HI data bus if the HREQ output is asserted. In this case,
all other HI control pins are ignored and the HI state is
not affected.
Signal Description
Signal/Pin Descriptions
Host Interface (HI) Port
1-13