AN1769 Freescale Semiconductor / Motorola, AN1769 Datasheet - Page 3

• Manufacturer Part Number: AN1769
• Description: Designing a Minimal PowerPC System
• Manufacturer: Freescale Semiconductor / Motorola

MOTOROLA
1.2 Conventions
Various conventions used in this document are as follows:
Occasionally, a name may have both forms; for example, the TS hardware signal may be detected in a
fragment of HDL code which refers to it as Òts_L.Ó
Part 2 Processor Design
The processor may be any member of the MPC60x or MPC7xx family. All such devices offer 64-bit bus
modes, and the MPC603x parts also offer a 32-bit bus interface which can make the memory design even
simpler at a cost of speed. Since only the MPC603x parts support this mode, it will not be used in this design
but it should be kept in mind where the number of parts or cost is even more important than speed.
Since all high-performance PowerPC processors use very similar bus interfaces, the choice of processor
may be based on cost and performance issues and not on the interface costs. For a simple system with only
one bus master, many signals on the processor bus may be ignored or wired to the desired state; refer to
Table 1 for more information.
SIGNAL
SIGNAL
signal
signal_L
name()
LTC1585
Power
Memory Controller
Lattice
2096V
DS1834
Reset
Figure 1. Typical Minimal System Block Diagram
Freescale Semiconductor, Inc.
16550 UART
Serial Port
For More Information On This Product,
Lattice
Active-high external signal (pin).
Active-low external signal (pin).
Active-high internal signal (net); used when describing the memory
controller.
Active-low internal signal (net); used when describing the memory
controller (Ô_LÕ indicates active low for internal signals).
A block of HDL code implementing a function.
Minimal PowerPC System Design
Go to: www.freescale.com
MPC60x, MPC7xx,
MPE60x, MPC7xx
(2) MCM69P737
512K PBSRAM
Main Memory
Processor
Motorola
Motorola
15 ns
(2) 74LCX245
Motorola
I/O Port
TS*
Motorola
MPC904
Start-up Code
Clock
(4) 29F800
4M Flash
Motorola
150 ns
(optional)
COP
3