
PRODUCT SPECIFICATION
11-1
PCI Interface
Chapter 11
by Gert Slavenburg, Ken-Sue Tan, Babu Kandimalla
11.1
NEW IN TM1300
TM1300 DMA read transactions use the more efficient
‘memory read multiple’ PCI transactions, unless explicit-
ly disabled. Section 11.7.5.
TM1300 contains an on-board PCI_CLK generator for
low-cost configurations. It can be enabled/disabled at
boot time. See Section 13.2.
TM1300 has a sideband control signal that allows glue-
less connection of simple slave peripherals directly to the
PCI bus wires. This can be used to connect Flash, ROM,
SRAM, UARTs, etc. with 8-bit data and demultiplexed
addresses. Refer to Chapter 22, “PCI-XIO External I/O
Bus.”
11.2
PCI OVERVIEW
TM1300 includes a PCI interface for easy integration into
personal computer applications—where the PCI-bus is
the standard for high-speed peripherals. In embedded
applications, with TM1300 serving as the main CPU, the
PCI bus can interface to peripheral devices that imple-
ment functions not provided by the on-chip peripherals.
See Figure 11-1.
The main function of the PCI interface is to connect the
TM1300 on-chip highway and PCI buses. A bus cycle on
the internal highway that targets an address mapped into
PCI space will cause the PCI interface to create a PCI
bus cycle. Similarly, a bus cycle on PCI that targets an
address mapped into TM1300 memory space will cause
the PCI interface to create a highway bus cycle targeted
at SDRAM. For some operations, the PCI interface is ex-
plicitly programmed by the DSPCPU.
From TM1300, only the DSPCPU and the image copro-
cessor (ICP) unit can cause the PCI interface to create
PCI bus cycles; the other on-chip peripherals cannot see
external hardware through the PCI interface. From PCI,
SDRAM and most of the registers in MMIO space can be
accessed by external PCI initiators.
The PCI interface implements DMA (also called block or
burst) and non-DMA transfers. DMA transfers are inter-
ruptible on 64-byte boundaries. The PCI interface can
service outbound (TM1300
→ PCI) and inbound (PCI →
TM1300) data flows simultaneously.
Table 11-1 lists some of the features of the PCI interface.
PCI Agent
TM1300
PCI Bus
Arbiter
Host CPU
(e.g., x86)
Interrupt
Controller
PCI Agent
TM1300
PCI Bus
Arbiter
a) TM1300 as peripheral
b) TM1300 as host CPU
PCI Bus
PCI Bridge
Figure 11-1. Two typical system implementations: (a) shows TM1300 as a PCI peripheral in a desktop PC, (b)
shows an embedded system with TM1300 as the host CPU.
Table 11-1. PCI interface characteristics
Characteristic
Comments
PCI Compliance
PCI Local Bus Specication Rev. 2.1
PCI Speed
Up to 33 MHz
Data bus width
32-bit only
Address space
32 bits (4 GB)
Voltage levels
Drive & receive at either 3.3 V or 5V
Burst mode
Yes, w/ double buffering so maxi-
mum transfer rate (132 MB/sec) is
sustainable
Posted write
Yes, can be disabled
PCI ‘special cycle’
Not recognized
PCI ‘memory write &
invalidate’
Supported for TM1300 as initiator
PCI ‘interrupt acknowl-
edge’
Not generated
PCI ‘dual-address
cycle’
Not generated