AMD AM186EM User Manual page 18

Figure 1-2 Am188EM Microcontroller Block Diagram
INT3/INTA1/IRQ
CLKOUTA
CLKOUTB
X2
X1
Clock and
Power
Management
V
CC
Unit
GND
Control
Registers
RES
Control
Registers
ARDY
SRDY
S2–S0
DT/R
Bus
DEN
Interface
HOLD Unit
HLDA
S6/
CLKDIV2
UZI
A19–A0
AO15–AO8
AD7–AD0
ALE
Note:
* All PIO signals are shared with other physical pins. See the pin descriptions in Chapter 3 and Table
3-1 on page 3-9 for information on shared functions.
1-4
INT2/INTA0
INT1/SELECT
INT4
INT0
NMI
Interrupt
Control Unit
Control
Registers
Refresh
Control
Unit
Execution
Unit
RD
LCS/ONCE0
WB
MCS3/RFSH
MCS2–MCS0
WR
RFSH2/ADEN
Features and Performance
TMROUT0 TMROUT1
TMRIN0 TMRIN1
Timer Control
Unit
0 1 (WDT) 2
Max Count B
Registers
Max Count A
Registers
16-Bit Count
Registers
Control
Registers
Control
PSRAM
Registers
Control
Unit
Chip-Select
Unit
PCS6/A2
PCS5/A1
PCS3–PCS0
UCS/ONCE1
DRQ0 DRQ1
DMA
Unit
0 1
20-Bit Source
Pointers
20-Bit Destination
Pointers
16-Bit Count
Registers
Control
Registers
PIO
Unit
Control
Registers
Asynchronous
Serial Port
Control
Registers
Synchronous Serial
Interface
SDATA
SCLK
SDEN0 SDEN1
PIO31–
PIO0*
TXD
RXD