Freescale Semiconductor DSP56366 - Manual (Page 115)

HDI08 – External Host Programmer’s Model
DSP56366 24-Bit Digital Signal Processor User Manual, Rev. 4
Freescale Semiconductor 6-21
6.6.1.3 ICR Double Host Request (HDRQ) Bit 2
The HDRQ bit determines the functions of the HOREQ/HTRQ and HACK/HRRQ signals as shown in
Table 6-11 .
6.6.1.4 ICR Host Flag 0 (HF0) Bit 3
The HF0 bit is used as a general purpose flag for host-to-DSP communication. HF0 may be set or cleared
by the host processor and cannot be changed by the DSP core. HF0 is reflected in the HSR on the DSP side
of the HDI08.
6.6.1.5 ICR Host Flag 1 (HF1) Bit 4
The HF1 bit is used as a general purpose flag for host-to-DSP communication. HF1 may be set or cleared
by the host processor and cannot be changed by the DSP core. HF1 is reflected in the HSR on the DSP side
of the HDI08.
Table 6-9 TREQ RREQ Interrupt Mode (HDM[2:0]=000 or HM[1:0]=00)
TREQ RREQ
HDRQ=0 HDRQ=1
HOREQ signal HTRQ signal HRRQ signal
0 0 No Interrupts (Polling) No Interrupts (Polling) No Interrupts (Polling)
0 1 RXDF Request (Interrupt) No Interrupts (Polling) RXDF Request (Interrupt)
1 0 TXDE Request (Interrupt) TXDE Request (Interrupt) No Interrupts (Polling)
1 1 RXDF and TXDE Requests (Interrupts) TXDE Request (Interrupt) RXDF Request (Interrupt)
Table 6-10 TREQ RREQ DMA Mode (HM1 ≠0 or HM0≠0)
TREQ RREQ HDRQ=0 HDRQ=1
HOREQ signal HTRQ signal HRRQ signal
0 0 No DMA request No DMA request No DMA request
0 1 DSP to Host Request (RX) No DMA request DSP to Host Request (RX)
1 0 Host to DSP Request (TX) Host to DSP Request (TX) No DMA request
1 1 Reserved Reserved Reserved
Table 6-11 HDRQ
HDRQ HOREQ/HTRQ pin HACK/HRRQ pin
0 HOREQ signal HACK signal
1 HTRQ signal HRRQ signal