Motorola DSP56301 - Manual (Page 46)

Host Interface (HI32)
2 -16 DSP56301 User’s Manual
HP40 HAD23 (pull up or down if not used)
1
HD15 disconnected
HP41 HAD24 (pull up or down if not used) 1 HD16 disconnected
HP42 HAD25 (pull up or down if not used)
1
HD17 disconnected
HP43 HAD26 (pull up or down if not used) 1 HD18 disconnected
HP44 HAD27 (pull up or down if not used)
1
HD19 disconnected
HP45 HAD28 (pull up or down if not used) 1 HD20 disconnected
HP46 HAD29 (pull up or down if not used)
1
HD21 disconnected
HP47 HAD30 (pull up or down if not used) 1 HD22 disconnected
HP48 HAD31 (pull up or down if not used)
1
HD23 disconnected
HP49 HRST HRST (Schmitt trigger buffer on input)
HP50 HINTA
PVCL Leave unconnected
1. HD23-HD16 Output is high impedance if HRF
≠
$0. Input is disconnected if HTF
≠
$0.
Table 2-12. Host Port Pins (HI32)
Signal
Name
PCI
Universal Bus Mode
Enhanced Universal Bus Mode GPIO
HP[7–0] HAD[15–0]
Address/Data Multiplexed Bus
Tri-state bidirectional bus.
During the first clock cycle of a
transaction HAD31-HAD0 contain the
physical byte address (32 bits).
During subsequent clock cycles,
HAD31-HAD0 contain data. HA[10–3]
Host Address Bus
Input pin.
Selects HI32 register to access. HA[10–3]
select the HI32 and HA[2–0] select the
particular register of the HI32 to be accessed. HIO[15–8]
GPIO
2
HP[15–8] HD[7–0]
Host Data Bus
Tri-state, bidirectional bus.
Transfers data between the host processor
and the HI32.
This bus is released (disconnected) when the
HI32 is not selected by HA[10-0]. The
HD[23–0] pins are driven by the HI32 during a
read access and are inputs to the HI32 during
a write access.
HD[23–16] outputs are high impedance if
HRF
≠
$0. HD[23–16] inputs are disconnected
if HTF
≠
$0.
Table 2-11. Summary of HI32 Signals and Modes (Continued)
Signal
Name
PCI Mode Enhanced Universal Bus Mode Universal Bus Mode GPIO Mode