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3.2.3
Bus Holders
3.3
Parallel I/O Ports
3.3.1
Enhanced 8-/16-Bit Host-Port Interface (HPI8/16)
TMS320VC5410A
Fixed-Point Digital Signal Processor
SPRS139G–NOVEMBER 2000–REVISED JANUARY 2005
The 5410A has two bus holder control bits, BH (BSCR[1]) and HBH (BSCR[2]), to control the bus keepers
of the address bus (A[16-0]), data bus (D[15-0]), and the HPI data bus (HD[7-0]). Bus keeper
enabling/disabling is described in Table 3-6.
Table 3-6. Bus Holder Control Bits
HPI16 PIN
0
0
0
0
1
1
1
1
BH
0
0
1
1
0
0
1
1
HBH
0
1
0
1
0
1
0
1
D[15-0]
OFF
OFF
ON
ON
OFF
OFF
ON
ON
A[16-0]
OFF
OFF
OFF
OFF
OFF
ON
OFF
ON
HD[7-0]
OFF
ON
OFF
ON
ON
ON
ON
ON
The 5410A 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 5410A can
interface easily with external devices through the I/O ports while requiring minimal off-chip ad-
dress-decoding circuits.
The 5410A 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 5410A 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 5410A 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 5410A 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 5410A.
Enhanced features:
Access to entire on-chip RAM through DMA bus
Capability to continue transferring during emulation stop
26
Functional Overview