DSP56303 FREESCALE [Freescale Semiconductor, Inc], DSP56303 Datasheet - Page 104

• Manufacturer Part Number: DSP56303
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Host Interface (HI08)
6.3 Overview
The HI08 is partitioned into two register banks, as Figure 6-1 shows. The host-side register bank
is accessible only to the host, and the DSP-side register bank is accessible only to the DSP core.
For the host, the HI08 appears as eight byte-wide locations mapped in its external address space.
The DSP-side registers appear to the DSP core as six 24-bit registers mapped into internal I/O X
memory space and therefore accessible via standard DSP56300 instructions and addressing
modes.
6-4
HCR
ISR
8
24
Control Registers
ISR = Interface Status Register
ICR = Interface Control Register
CVR = Command Vector Register
IVR = Interrupt Vector Register
Control Registers
HCR = Host Control Register
HSR = Host Status Register
HPCR = Host Port Control Register
HBAR = Host Base Address Register
HSR
ICR
24
8
HDDR
CVR
8
24
Figure 6-1. HI08 Block Diagram
HDR
IVR
DSP-Side Registers
DSP56303 User’s Manual, Rev. 2
DSP Peripheral Data Bus
8
24
Core DMA Data Bus
3
Host-Side Registers
Comparator
HBAR
Latch
Address
HOST Bus
8
24
5
3
Data Registers
HTX = Host Transmit Register
HRX = Host Receive Register
HDDR = Host Data Direction Register
HDR = Host Data Register
Data Registers
RXH = Receive Register High
RXM = Receive Register Middle
RXL = Receive Register Low
TXH = Transmit Register High
TXM = Transmit Register Middle
TXL = Transmit Register Low
RXH
24
HPCR
8
RXM
8
24
RXL
HTX
8
24
24
TXH
24
8
HRX
TXM
Freescale Semiconductor
8
24
24
TXL
8
DSP
Side
Host
Side