Servicing The Hi; Hi-Host Processor Data Transfer; Figure 4-14 Host Processor Transfer Timing - Motorola DSP56012 User Manual

HOA0–HOA2
HR/W
HEN
H[7:0]
Write
4.4.7

Servicing the HI

The HI can be serviced by using one of the following protocols:
• Polling
• Interrupts, which can be either:
– non-DMA
– DMA
From the host processor viewpoint, the service consists of making a data transfer,
since this is the only way to reset the appropriate status bits.
4.4.7.1 HI—Host Processor Data Transfer
The HI looks like Static RAM to the host processor. Accordingly, in order to transfer
data with the HI, the host processor:
1. asserts the Host Address (HOA[2:0]) to select the register to be read or written;
2. asserts HR/W to select the HI for the current access, and
MOTOROLA
Data
Latched
In Host

Figure 4-14 Host Processor Transfer Timing

DSP56012 User's Manual
Parallel Host Interface
Host Interface (HI)
3
8
+5
Read
+5
DSP56012
HOA0–HOA2
HR/W
HEN
H[7:0]
HOREQ
HACK
AA0322.11
4-37