AM186ER-25KCW AMD [Advanced Micro Devices], AM186ER-25KCW Datasheet - Page 15

• Manufacturer Part Number: AM186ER-25KCW
• Description: High-Performance, 80C186- and 80C188-Compatible, 16-Bit Embedded Microcontrollers with RAM
• Manufacturer: AMD [Advanced Micro Devices]

Direct Memory Interface Example
Figure 1 illustrates the direct interface to memory of the
Am186ER microcontroller. The A19–A0 bus connects
to the memory address inputs, the AD bus connects to
the data inputs and outputs, and the chip selects con-
nect to the memory chip-select inputs.
Figure 1 also shows an implementation of an RS-232
console or modem communications port. The RS-232-
to-CMOS voltage-level converter is required for the
electrical interface with the external device.
COMPARISON OF THE Am186™ER AND
80C186 MICROCONTROLLERS
Figure 1 shows an example system using a 50-MHz
Am186ER microcontroller. Figure 2 shows a compara-
ble system implementation with an 80C186 microcon-
troller. Because of its superior integration, the
Am186ER system does not require the support devices
required on the 80C186 example system. In addition,
the Am186ER microcontroller provides significantly
better performance with its 50-MHz clock rate.
40-MHz
Crystal
Am186
TM
Figure 2.
ER and Am188
X2
X1
AD15–AD0
INT2–INT0
Timer 0–2
DMA 0–1
CLKOUT
Typical 80C186 System Design
PCS0
INT3
UCS
BHE
LCS
ALE
WR
RD
A0
TM
ER Microcontrollers Data Sheet
LATCH
12.5-MHz
Crystal
Am29F400
20 MHz
OE
WE
Address
Data
Serial Port
CS
Figure 1. Am186™ER 50-MHz Example
Flash
Converter
RS-232
Level
PIOs
Serial
Port
X2
X1
TXD
RXD
Microcontroller
Converter
Am186ER
System Design
32 Kbyte
RS-232
Data
OE
Address
CS
Level
WE
SRAM
WE
SRAM
AD15–AD0
INT4–INT0
CLKOUTA
Timer 0–2
DMA 0–1
A19–A0
UCS
WR
RD
Am29F400
WE
Address
Data
OE
CS
50 MHz
Flash
15