
File: pci.fm5, modified 7/23/99
PRELIMINARY INFORMATION
10-1
PCI Interface
Chapter 10
by Gert Slavenburg, Ken-Sue Tan, Babu Kandimalla
10.1
NEW IN TM1100
TM1100 DMA read transactions use the more efficient
“memory read multiple” PCI transactions, unless explic-
TM1100 contains an on board PCI_CLK generator for
low-cost configurations. It can be enabled/disabled at
TM1100 has a sideband control signal that allows glue-
less connection of simple slave peripherals direct to the
PCI bus wires. This can be used to connect Flash, ROM,
SRAM, UARTs etc. with 8 bit data and demultiplexed ad-
10.2
PCI OVERVIEW
TM1100 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 TM1100 serving as the main CPU, the
PCI bus can interface to peripheral devices that imple-
ment functions not provided by the on-chip peripherals.
The main function of the PCI interface is to connect the
TM1100 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 TM1100 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 TM1100, only the DSPCPU and the ICP (image co-
processor) 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 a most of the registers in MMIO space can be ac-
cessed 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 (TM1100
→ PCI) and inbound (PCI →
TM1100) data flows simultaneously.
Table 10-1 lists some of the features of the PCI interface.
PCI Agent
TM1100
PCI Bus
Arbiter
Host CPU
(e.g., x86)
Interrupt
Controller
PCI Agent
TM1100
PCI Bus
Arbiter
a) TM1100 as peripheral
b) TM1100 as host CPU
PCI Bus
PCI Bridge
Figure 10-1. Two typical system implementations. (a) shows TM1100 as a PCI peripheral in a desktop PC. (b)
shows an embedded system with TM1100 as the host CPU.
Table 10-1. PCI Interface Characteristics
Characteristic
Comments
PCI Compliance
PCI Local Bus Specication Revi-
sion 2.1
PCI Speed
Up to 33 MHz
Data bus width
32-bit only
Address space
32 bits (4G bytes)
Voltage levels
Drive & receive at either 3.3V or 5V
Burst mode
Yes, w/ double buffering so maxi-
mum transfer rate (132 MB/s) is sus-
tainable
Posted write
Yes, can be disabled
PCI ‘special cycle’
Not recognized
PCI ‘memory write &
invalidate’
Supported for TM1100 as initiator
PCI ‘interrupt acknowl-
edge’
Not generated
PCI ‘dual-address
cycle’
Not generated