SD188ES/SD188EM Demonstration Board User’s Manual
2-6
1.1
Figure 2-3. Am188EM Microcontroller Block Diagram
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
Contro
l
Registers
Control
Registers
0
1 (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
V
CC
GND
TMRIN0
TMRIN1
ARDY
SRDY
DT/R
DEN
HOLD
HLDA
Asynchronous
Serial Port
Synchronous Serial
Interface
TXD
RXD
SCLK
SDATA
SDEN0 SDEN1
NMI
A19-A0
AD7-AD0
ALE
RFSH2/ADEN
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
*
PIO31-
PIO0
Co
n
tr
o
l
Reg
ister
s
S6
/
CLKDIV2
UZI
AO15-AO8
frtbook : newch2 Page 6 Monday, June 2, 1997 3:37 PM