Host Interface (HI08)
Servicing the Host Interface
MOTOROLA
DSP56309UM/D 6-33
HREQ is normally connected to the maskable interrupt input of the host processor. The
host processor acknowledges host interrupts by executing an interrupt service routine.
The host processor can test the two LSBs (RXDF and TXDE) of the ISR register to
determine the interrupt source, as in
. The host processor interrupt service
routine must read or write the appropriate HI08 data register to clear the interrupt.
HREQ/HTRQ and/or HRRQ is deasserted under either of the following conditions:
¥ The enabled request is cleared or masked.
¥ The DSP is reset.
If the host processor is a member of the MC68000 family, there is no need for the
additional step when the host processor reads the ISR to determine how to respond to an
interrupt generated by the DSP56309. Instead, the DSP56309 automatically sources the
contents of the IVR on the data bus when the host processor acknowledges the interrupt
by asserting HACK. The contents of the IVR are placed on the host data bus while
HREQ/TRQ (or HRRQ) and HACK are simultaneously asserted. The IVR data tells the
MC680XX host processor which interrupt routine to execute to service the DSP56309.
shows the HI08 programming model.
Figure 6-16
HI08 Host Request Structure
$0
HF1
HF0
HBEND TREQ
RREQ
ICR
Enable
7
0
INIT
0
0
Status
7
0
$2
HF3
HF2
TRDY
TXDE
RXDF
ISR
HREQ
0
0
Host Request
Asserted
HRRQ
HREQ
HTRQ
AA0672
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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