Parallel Host Interface
Host Interface (HI)

MOTOROLA DSP56012 User’s Manual 4-57

Figure 4-32 Bits Used for DSP to Host Transfer

HOST DSP56012
RXDF—RECEIVE DATA REGISTER FULL
1 = INDICATES THE RECIEVE BYTE REGISTERS (RXH, RXM, RXL)
CONTAIN DATA FROM THE DSP.
0 = CLEARED BY READING RXL.
HTDE—HOST TRANSMIT DATA EMPTY
1 = HOTX IS EMPTY AND CAN BE WRITTEN BY DSP.
0 = HOTX IS FULL.
HTIE—HOST TRANSMIT INTERRUPT ENABLE
1 = ENABLE THE DSP INTERRUPT TO P:$0032.
0 = DISABLE THE DSP INTERRUPT TO P:$0032.
DSP INTERRUPT IS CAUSED BY HTDE = 1
RREQ —RECEIVE REQUEST ENABLE (USED TO CONTROL THE HOREQ PIN)
1 = ENABLE INTERRUPT REQUESTS CREATED BY RXDF.
0 = DISABLE INTERRUPT REQUESTS.
$2
INTERRUPT
STATUS
REGISTER (ISR)
(READ ONLY)
$0
X:$FFE8 HOST STATUS
REGISTER (HSR)
(READ ONLY)
HOST CONTROL
REGISTER (HCR)
(READ/WRITE)
INTERRUPT
CONTROL
REGISTER (ICR)
(READ/WRITE)
X:$FFE8
HOREQ HF3 HF2 TXDE RXDF
70
0DMA
654321
TRDY DMA HF1 HF0 HTDE HRDF
70
00
654321
HCP
INIT HF1 HF0 TREQ RREQ
70
HM0HM1
654321
00HF3 HF2 HTIE HRIE
70
00
654321
HCIE
MODES

AA0339