AMD Am186 ES, User Manual, Page: 18 / 192

Features and Performance 1-4
Figure 1-1 Am186ES Microcontroller Block Diagram
Notes:
*All PIO signals are shared with other physical pins. See the pin descriptions in Chapter 3 and Table
3-1 on page 3-13 for information on shared functions.
** PWD, INT5, INT6, RTS1/RTR1, and CTS1/ENRX1 are multiplexed with INT2/INTA0, DRQ0,
DRQ1, PCS3, and PCS2 respectively. See the pin descriptions in Chapter 3.
S2–S0
Interrupt
Control Unit
Timer Control
Unit
DMA
Unit
Bus
Interface
Unit
Execution
Unit
Chip-Select
Unit
Clock and
Power
Management
Unit
Control
Registers
16-Bit Count
Registers
Max Count A
Registers
16-Bit Count
Registers
20-Bit Destination
Pointers
20-Bit Source
Pointers
Control
Registers
Control
Registers
Control
Registers
0 1 2 0 1
Max Count B
Registers
Refresh
Control
Unit
Control
Registers
Control
Registers
Control
Registers
CLKOUTB
CLKOUTA
INT6–INT4**
INT3/INTA1/IRQ
INT2/INTA0**
INT1/SELECT
INT0
TMROUT0 TMROUT1
DRQ0** DRQ1**
V
CC
GND
TMRIN0 TMRIN1
ARDY
SRDY
DT/R
DEN/DS
HOLD
HLDA
Asynchronous
Serial Port 0
TXD0
RXD0
NMI
A19–A0
AD15–AD0
ALE
BHE/ADEN
WR
WLB
WHB
RD
RES
LCS/ONCE0
MCS2–MCS0
PCS6/A2
PCS3–PCS0**
PCS5/A1
UCS/ONCE1
X2
X1
PSRAM
Control
Unit
MCS3/RFSH
PIO
Unit
PIO31–PIO0*
Co
ntro
l
R
egi
ste
rs
S6/LOCK/
UZI
CLKDIV2
TXD1
RXD1
CTS0/ENRX0
CTS1/ENRX1**
RTS0/RTR0
RTS1/RTR1**
Watchdog
Timer (WDT)
Pulse
Width
Demod-
ulator
PWD**
Asynchronous
Serial Port 1