Features and Performance 1-5

Figure 1-2 Am188ER Microcontroller Block Diagram

Notes:
1. All PIO signals are shared with other physical pins. See the pin descriptions in Chapter 3 an dTable 3-1 on page 3-10 for information on shared functions.
20-Bit Source
Pointers
Interrupt
Control Unit
Timer Control
Unit DMA
Unit
Bus
Interface
Unit
32 Kbyte
RAM
(32K x 8) 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
Control
Registers
Control
Registers
Control
Registers
01 (WDT)2 0 1
Max Count B
Registers
Refresh
Control
Unit
Control
Registers Control
Registers Control
Registers
CLKOUTB
CLKOUTA INT4
INT3/INTA1/IRQ
INT2/INTA0
INT1/SELECT
INT0 TMROUT0 TMROUT1
DRQ0 DRQ1
VCC
GND
TMRIN0 TMRIN1
Asynchronous
Serial Port
Synchronous Serial
Interface
TXD
RXD
SCLK SDATA
SDEN0 SDEN1
NMI
A19–A0
AD7–AD0
ALE
WR
WB
RD
RES
LCS/ONCE0
MCS2–MCS0
PCS6/A2
PCS3–PCS0
PCS5/A1
UCS/ONCE1
X2
X1
Control
Registers
PSRAM
Control
Unit
MCS3/RFSH
PIO
Unit PIO31–
PIO01
Control
Registers
AO15–AO8
RFSH2/ADEN
Execution
Unit
ARDY
SRDY
DT/R
DEN
HOLD
HLDA
S6/
UZI/
CLKSEL2
CLKSEL1
S1/IMDIS
S0/SREN
S2