Stereo System User Manual

4-52 DSP56012 User’s Manual MOTOROLA
Parallel Host Interface
Host Interface (HI)
Figure 4-27 Host Command
$17—DEFAULT
VIEW FROM HOST VIEW FROM DSP56012
1. WRITE CVR WITH DESIRED HV.
HC HOST COMMAND
2. SET HC = 1.
3. HCP IS SET UNTIL INTERRUPT IS ACKNOWLEDGED. 4. HOST COMMAND IS MASKED UNTIL HCIE = 1.
5. WHEN THE HOST COMMAND interrupt IS ACKNOWLEDGED, THE HC BIT IS CLEARED BY THE HOST COMMAND LOGIC. HC CAN BE READ AS A STATUS BIT.
HCP
HOST COMMAND PENDING
interrupt VECTOR TABLE
HCIE
HOST COMMAND INTERRUPT ENABLE
P:$007E
AVAILABLE FOR HOST COMMAND
FAST INTERRUPT
OR
LONG INTERRUPT
$1
COMMAND VECTOR REGISTER (CVR)
HC—HOST COMMAND (STATUS)
P:$0000
HOST COMMAND DEFAULT VECTOR
P:$0034
AVAILABLE FOR HOST COMMAND AVAILABLE FOR HOST COMMAND
interrupt VECTOR
ADDRESS = HV x 2
$1
COMMAND VECTOR REGISTER (CVR)
1
HOST VECTOR (HV)
70
0
5
X:$FFE8
HOST CONTROL REGISTER (HCR)
0
HF3 HF2 HTIE HRIE
70
00
65432 1
1
X:$FFE9
HOST STATUS REGISTER (HSR)
DMA
HF1 HF0 HTDE HRDF
70
00
65432 1
1
AA0336
0
HOST VECTOR (HV)
70
0
5
Note: When using the SAI and DAX peripherals, do not use interrupt vector addresses P:$0040–$004A, $0050, $0052, and $0056.