SMJ320VC5416 Datasheet, PDF (29/92 Pages) Texas Instruments – Fixed-Point Digital Signal Processor

Functional Overview
3.6.3 Bus Holders
The 5416 has two bus holder control bits, BH (BSCR[1]) and HBH (BSCR[2]), to control the bus keepers of
the address bus (A[17–0]), data bus (D[15–0]), and the HPI data bus (HD[7–0]). Bus keeper enabling/disabling
is described in Table 3–5.
HPI16 PIN
0
0
0
0
1
1
1
1
Table 3–6. Bus Holder Control Bits
BH
HBH
D[15–0]
A[17–0]
0
0
OFF
OFF
0
1
OFF
OFF
1
0
ON
OFF
1
1
ON
OFF
0
0
OFF
OFF
0
1
OFF
ON
1
0
ON
OFF
1
1
ON
ON
HD[7–0]
OFF
ON
OFF
ON
ON
ON
ON
ON
3.7 Parallel I/O Ports
The 5416 has a total of 64K I/O ports. These ports can be addressed by the PORTR instruction or the PORTW
instruction. The IS signal indicates a read/write operation through an I/O port. The 5416 can interface easily
with external devices through the I/O ports while requiring minimal off-chip address-decoding circuits.
3.7.1 Enhanced 8-/16-Bit Host-Port Interface (HPI8/16)
The 5416 host-port interface, also referred to as the HPI8/16, is an enhanced version of the standard 8-bit HPI
found on earlier TMS320C54x DSPs (542, 545, 548, and 549). The 5416 HPI can be used to interface to
an 8-bit or 16-bit host. When the address and data buses for external I/O is not used (to interface to external
devices in program/data/IO spaces), the 5416 HPI can be configured as an HPI16 to interface to a 16-bit host.
This configuration can be accomplished by connecting the HPI16 pin to logic “1”.
When the HPI16 pin is connected to a logic “0”, the 5416 HPI is configured as an HPI8. The HPI8 is an 8-bit
parallel port for interprocessor communication. The features of the HPI8 include:
Standard features:
• Sequential transfers (with autoincrement) or random-access transfers
• Host interrupt and C54x interrupt capability
• Multiple data strobes and control pins for interface flexibility
The HPI8 interface consists of an 8-bit bidirectional data bus and various control signals. Sixteen-bit transfers
are accomplished in two parts with the HBIL input designating high or low byte. The host communicates with
the HPI8 through three dedicated registers — the HPI address register (HPIA), the HPI data register (HPID),
and the HPI control register (HPIC). The HPIA and HPID registers are only accessible by the host, and the
HPIC register is accessible by both the host and the 5416.
Enhanced features:
• Access to entire on-chip RAM through DMA bus
• Capability to continue transferring during emulation stop
TMS320C54x and C54x are trademarks of Texas Instruments.
April 2003 – Revised July 2003
SGUS035A
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