Host Interface (HDI08)
HDI08 – External Host Programmer’s Model
MOTOROLA
DSP56367
8-27
8.6.3.5
ISR Host Flag 3 (HF3) Bit 4
The HF3 bit in the ISR indicates the state of host flag 3 in the HCR on the DSP side. HF3 can
be changed only by the DSP (see Section 8.5.3.4).
8.6.3.6
ISR Reserved Bits 5-6
These bits are reserved. They read as zero and should be written with zero for future
compatibility.
8.6.3.7
ISR Host Request (HREQ) Bit 7
The HREQ bit indicates the status of the external host request output signal (HOREQ) if
HDRQ is cleared. If HDRQ is set, it indicates the status of the external transmit and receive
request output signals (HTRQ and HRRQ).
The HREQ bit may be set from either or both of two conditions – either the receive byte
registers are full or the transmit byte registers are empty. These conditions are indicated by the
ISR RXDF and TXDE status bits, respectively. If the interrupt source has been enabled by the
associated request enable bit in the ICR, HREQ is set if one or more of the two enabled
interrupt sources is set.
8.6.4
INTERRUPT VECTOR REGISTER (IVR)
The IVR is an 8-bit read/write register which typically contains the interrupt vector number
used with MC68000 Family processor vectored interrupts. Only the host processor can read
and write this register. The contents of IVR are placed on the host data bus (H0–H7) when
both the HOREQ and HACK signals are asserted. The contents of this register are initialized
to $0F by hardware or software reset, which corresponds to the uninitialized interrupt vector
in the MC68000 Family.
Table 8-14 Host Request Status (HREQ)
HREQ
Status [HDRQ=0]
Status [HDRQ=1]
0
HOREQ deasserted; no host processor interrupt is requested
HTRQ and HRRQ deasserted; no host processor interrupts are
requested
1
HOREQ asserted; a host processor interrupt is requested
HTRQ and/or HRRQ asserted; host processor interrupts are
requested
Figure 8-15 Interrupt Vector Register (IVR)
7
6
5
4
3
2
1
0
IV7
IV6
IV5
IV4
IV3
IV2
IV1
IV0
Summary of Contents for DSP56367
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Page 22: ...xxii MOTOROLA List of Figures Figure Number Title Page Number ...
Page 26: ...xxvi MOTOROLA List of Tables Table Number Title Page Number ...
Page 148: ...4 6 DSP56367 MOTOROLA Design Considerations PLL Performance Issues ...
Page 248: ...9 30 DSP56367 MOTOROLA Serial Host Interface SHI Programming Considerations ...
Page 306: ...10 58 DSP56367 MOTOROLA Enhanced Serial Audio Interface ESAI ESAI Initialization Examples ...
Page 389: ...Bootstrap ROM Contents MOTOROLA DSP56367 A 15 end ...
Page 390: ...A 16 DSP56367 MOTOROLA Bootstrap ROM Contents ...
Page 432: ...C 8 DSP56367 MOTOROLA JTAG BSDL ...
Page 484: ...D 52 DSP56367 MOTOROLA Programmer s Reference ...
Page 490: ...E 6 DSP56367 MOTOROLA Power Consumption Benchmark ...
Page 516: ...F 26 DSP56367 MOTOROLA IBIS Model ...
Page 522: ...Index 6 MOTOROLA Index ...
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