LCS/ONCE0 ................................................................................................................... 33
MCS3/RFSH/PIO25 ....................................................................................................... 33
MCS2–MCS0 (MCS2/PIO24, MCS1/PIO15, MCS0/PIO14) .......................................... 34
NMI ................................................................................................................................ 34
PCS3–PCS0 (PCS3/PIO19, PCS2/PIO18, PCS1/PIO17, PCS0/PIO16) ...................... 34
PCS5/A1/PIO3 ............................................................................................................... 34
PCS6/A2/PIO2 ............................................................................................................... 34
PIO31–PIO0 (Shared) .................................................................................................... 35
RD .................................................................................................................................. 35
RES ................................................................................................................................ 35
RFSH2/ADEN (Am188™ER Microcontroller Only) ........................................................ 35
RXD/PIO28 .................................................................................................................... 35
S2 ................................................................................................................................... 35
S1/IMDIS ........................................................................................................................ 37
S0/SREN ........................................................................................................................ 37
S6/CLKSEL1/PIO29 ....................................................................................................... 37
SCLK/PIO20 .................................................................................................................. 37
SDATA/PIO21 ................................................................................................................ 37
SDEN1/PIO23, SDEN0/PIO22 ....................................................................................... 37
SRDY/PIO6 .................................................................................................................... 38
TMRIN0/PIO11 .............................................................................................................. 38
TMRIN1/PIO0 ................................................................................................................ 38
TMROUT0/PIO10 .......................................................................................................... 38
TMROUT1/PIO1 ............................................................................................................ 38
TXD/PIO27 ..................................................................................................................... 38
UCS/ONCE1 .................................................................................................................. 38
UZI/CLKSEL2/PIO26 ..................................................................................................... 38
V
................................................................................................................................ 39
CC
WHB (Am186™ER Microcontroller Only) ...................................................................... 39
WLB (Am186™ER Microcontroller Only)........................................................................ 39
WB (Am188™ER Microcontroller Only) ......................................................................... 39
WR ................................................................................................................................. 39
X1 ................................................................................................................................... 39
X2 ................................................................................................................................... 39
Functional Description ............................................................................................................... 40
Memory Organization ..................................................................................................... 40
I/O Space ....................................................................................................................... 40
Bus Operation ............................................................................................................................ 41
Bus Interface Unit ...................................................................................................................... 41
Nonmultiplexed Address Bus ......................................................................................... 41
Byte Write Enables ........................................................................................................ 41
Output Enable ................................................................................................................ 41
Pseudo Static RAM (PSRAM) Support .......................................................................... 44
Peripheral Control Block (PCB) ................................................................................................. 44
Reading and Writing the PCB ........................................................................................ 44
Clock and Power Management .................................................................................................. 44
Phase-Locked Loop (PLL) ............................................................................................. 44
Crystal-Driven Clock Source .......................................................................................... 45
External Source Clock ................................................................................................... 45
System Clocks ............................................................................................................... 48
Power-Save Operation ................................................................................................... 48
Initialization and Processor Reset .................................................................................. 48
Reset Configuration Register ......................................................................................... 48
6
Am186TMER and Am188TMER Microcontrollers Data Sheet
AMD [ AMD ]
