Functional Overview
3.7.2 HPI Nonmultiplexed Mode
In
nonmultiplexed
mode, a host with separate address/data buses can access the HPI16 data register (HPID)
via the HD 16-bit bidirectional data bus, and the address register (HPIA) via the 23-bit HA address bus. The
host initiates the access with the strobe signals (HDS1, HDS2, HCS) and controls the direction of the access
with the HR/W signal. The HPI16 can stall host accesses via the HRDY signal. Note that the HPIC register
is not available in
nonmultiplexed
mode since there are no HCNTL signals available. All host accesses initiate
a DMA read or write access. Figure 3–10 shows a block diagram of the HPI16 in
nonmultiplexed
mode.
HOST
DATA[15:0]
HPI16
PPD[15:0]
HINT
Address[22:0]
VCC
HCNTL0
HCNTL1
HBIL
HAS
R/W
Data Strobes
READY
HRDY
HR/W
HDS1, HDS2, HCS
HPID[15:0]
DMA
54xx
CPU
Figure 3–10. Host-Port Interface — Nonmultiplexed Mode
Address (Hex)
0000
Reserved
005F
0060
DARAM0
1FFF
2000
DARAM1
3FFF
4000
DARAM2†
5FFF
6000
DARAM3†
7FFF
8000
DARAM4†
9FFF
A000
Reserved
FFFF
† Reserved on 5404 devices
Figure 3–11. HPI Memory Map
Internal
Memory
November 2001 – Revised July 2003
SPRS007B
23
TI [ TEXAS INSTRUMENTS ]
