Chapter 1. Overview
1-7
System Design
to 2 stop bits in 1/16-bit increments. Receive and transmit FIFOs minimize CPU service
calls. A wide variety of error detection and maskable interrupt capability is provided.
Using a programmable prescaler or an external source, the MCF5272 system clock
supports various baud rates. Modem support is provided with request-to-send (RTS) and
clear-to-send (CTS) lines available externally. Full-duplex autoecho loopback, local
loopback, and remote loopback modes can be selected.
The UART can be programmed to interrupt or wake-up the CPU on various normal or
abnormal events. To reduce power consumption, the UART can be disabled by software if
not in use.
1.2.4 Timer Module
The timer module contains five timers arranged in two submodules. One submodule
contains a programmable software watchdog timer. The other contains four independent,
identical general-purpose timer units, each containing a free-running 16-bit timer for use in
various modes, including capturing the timer value with an external event, counting
external events, or triggering an external signal or interrupting the CPU when the timer
reaches a set value. Each unit has an 8-bit prescaler for deriving the clock input frequency
from the system clock or external clock input. The output pin associated with each timer
has programmable modes.
To reduce power consumption, the timer module can be disabled by software.
1.2.5 Test Access Port
For system diagnostics and manufacturing testing, the MCF5272 includes user-accessible
test logic that complies with the IEEE 1149.1 standard for boundary scan testing, often
referred to as JTAG (Joint Test Action Group). The IEEE 1149.1 Standard provides more
information.
1.3 System Design
This section presents issues to consider when designing with the MCF5272. It describes
differences between the MCF5272 (core and peripherals) and various other standard
components that are replaced by moving to an integrated device like the MCF5272.
1.3.1 System Bus Configuration
The MCF5272 has flexibility in its system bus interfacing due to the dynamic bus sizing
feature in which 32-,16-, and 8-bit data bus sizes are programmable on a per-chip select
basis. The programmable nature of the strobe signals (including OE/RD, R/W, BS[3:0], and
CS
n
) should ensure that external decode logic is minimal or nonexistent. Configuration
software is required upon power-on reset before chip-selected devices can be used, except
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...