Chapter 3: Hardware
R-Engine-D
3-6
Signal
Pin
Function
P1
Timer1 output
ADC clock
5MHz U12
P3
/PCS5
U4 SCC2692 UART chip select at base I/O address 0x0500
P4
/DT
Step Two jumper
P7 A17
Upper address line –
Never use by application
P8 P18
Upper address line –
Never use by application
P17
1
/PCS
/CS for U18 HC138
P20
SCLK
Synchronous Clock for U14, U15, and U17
P21
SDAT
Serial Interface for U14, 15, and U17
P22
SDEN0
Interface with RTC, EEPROM
/INT0
upt.
J2 pin 8
U4 SCC2692 Dual UART interr
P27
J2 pin 34
TxD0
P28
J2 pin 32
RxD0
P29
J3 pin 3
Reserved for EEPROM, LED, RTC, and Watchdog timer
P30
INT4
Interrupt used by Compact Flash interface
P31
INT2
Tied to DS1337 RTC alarm
Ta
.2 I/
used for
3.6
I/O Mapped Devices
I/O Space
evices can use I/O mapping for access. You can access such I/O devices with
inportb
(port)
function void
io_wait
(char wait) to define
r 5 of the Am186ER User’s Manual.
ble 3
O lines
on-board components
External I/O d
or
outportb
(port,dat). These functions will transfer one byte or word of data to the specified I/O address.
The external I/O space is 64K, ranging from 0x0000 to 0xffff.
The default I/O access time is 15 wait states. You may use the
the I/O wait states from 0 to 15. The system clock is 100 ns for both CPUs, while the CPU clock is 25ns
for the Am186ER and 12.5ns for the R1100. Details regarding this can be found in the Software chapter,
and in the Am186ER User’s Manual. Slower components, such as most LCD interfaces, might find the
maximum programmable wait state of 15 cycles still insufficient. Due to the high bus speed of the system,
some components need to be attached to I/O pins directly.
For details regarding the chip select unit, please see Chapte
The table below shows more information about I/O mapping.
I/O space
Select
Location
Usage
0x0000-0x00ff
P16
/PCS0
J1 pin 19=
USER*
0x0100-0x01ff
/PCS1
U18 pin 4
HC138
0x0200-0x02ff
/PCS2
J2 pin 22=P18
, RTC
EEPROM
0x0300-0x03ff
/PCS3
J2 pin 31=P19
USER
0x0400-0x04ff /PCS4
Reserved
0x0500-0x05ff
/PCS5
J2 pin 15=P3
SCC26C92
0x0600-0x06ff
/PCS6
J2 pin 27 = P2
USER
*PCS0 may be use
p
l
C-0, P50, P100, MM-A.
d for other TERN eriphera boards, such as F