HDI08 – DSP-Side Programmer’s Model
DSP56366 24-Bit Digital Signal Processor User Manual, Rev. 4
Freescale Semiconductor 6-5
Figure 6-1 HDI08 Block Diagram
6.5 HDI08 – DSP-Side Programmer’s Model

The DSP core threats the HDI08 as a memory-mapped peripheral occupying eight 24-bit words in X data

memory space. The DSP may use the HDI08 as a normal memory-mapped peripheral, employing either

standard polled or interrupt-driven programming techniques. Separate transmit and receive data registers

are double-buffered to allow the DSP and host processor to transfer data efficiently at high speed. Direct

memory mapping allows the DSP core to communicate with the HDI08 registers using standard

instructions and addressing modes. In addition, the MOVEP instruction allows direct data transfers

between the DSP memory and the HDI08 registers or vice-versa. The HOTX and HORX registers may be

serviced by the on-chip DMA controller for data transfers.

RXLTXMTXH
8
HPCR
Latch RXLIVRCVRICR
24
24
HDDRHCR HSR HDR
24 24 24 2424

DSP Peripheral Data Bus

8888
88
5
3

HOST Bus

Address
Comparator
3
8
8
RXM
2424
HBAR
ISR
8
HORHOTX
24

Core DMA Data Bus

24
24
8
RXH
8
HCR Host Control Register
HSR Host Status Register
HPCR Host Port Control Register
HBAR Host Base Address register
HOTX Host Transmit register
HORX Ho st Receive register
HDDR Host Data Direction Register
HDR Host Data Register
ICR Interface Control Register
CVR Command Vector Register
ISR Interface Status Register
IVR Interrupt Vector Register
RXH/RXM/RXL Receive Register High/Middle/Low
TXH/TXM/TXL Transmit Register High/Middle/Low