MAX126EVKIT Maxim Integrated Products, MAX126EVKIT Datasheet - Page 10

• Manufacturer Part Number: MAX126EVKIT
• Description: EVAL KIT FOR MAX126
• Manufacturer: Maxim Integrated Products

Specifications of MAX126EVKIT

• Number Of Adc's: 4
• Number Of Bits: 14
• Sampling Rate (per Second): 250k
• Data Interface: Parallel
• Inputs Per Adc: 2 Single
• Input Range: ±2.5 V
• Power (typ) @ Conditions: 165mW @ 250kSPS
• Voltage Supply Source: Analog and Digital, Dual ±
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX126
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

68HC16MOD-16WIDE
The 68HC16MOD-16WIDE module uses a phase-locked
loop (PLL) to set its bus speed. Crystal Y1 is a
32.768kHz frequency reference. The internal oscillator
runs 256 times faster than the external crystal. When the
68HC16MOD-16WIDE module is reset, it waits for the
PLL to lock before it executes any software. After the
PLL locks onto the reference frequency, the software
doubles the clock speed by writing to the clock synthe-
sizer control register, selecting a bus speed of
16.78MHz.
U5 and U8, the user RAM area, are 32kbyte CMOS stat-
ic RAMs.
The 74HCT245 octal buffers let the 68HC16MOD-
16WIDE module access a 16-bit port on the interface
connectors. This memory-mapped port consists of sep-
arate read and write strobes, four chip selects, four
address LSBs, and sixteen data bits.
J3 is an RS-232 serial port, designed to be compatible
with the IBM PC 9-pin serial port. Use a straight-
through DB9 male-to-female cable to connect J3 to this
port. If the only available serial port has a 25-pin con-
nector, you may use a standard 25-pin to 9-pin
adapter. Table 1 shows the pinout of J3.
The MAX233 is an RS-232 interface voltage level-shifter
with two transmitters and two receivers. It includes a
built-in charge pump with internal capacitors that gener-
ates the output voltages necessary to drive RS-232 lines.
The 20 x 2 pin headers (P1 and P2) connect the
68HC16MOD-16WIDE module to a Maxim EV kit. Table
2 lists the function of each pin.
The 68HC16 µC generates various enable signals for
different address ranges. The ROM and RAM enable
signals are fed directly to the respective chips. Several
additional signals (P1–33 to P1–36) are available on the
data connector to be used by Maxim EV kits. Table 3
outlines the address ranges for each of the elements
found on the 68HC16MOD-16WIDE module, and Table
4 is a truth table that describes the logic for each of the
module’s chip-select outputs. Because the addresses
are not completely decoded, the boot ROM and has a
shadow at address 08000 hex.
2
_______________________________________________________________________________________
40-Pin Connectors P1 and P2
Serial Communications
Address Ranges
The boot ROM, U3, is configured as an 8-bit memory
device. Resistor R4 pulls data bit 0 low during system
reset, forcing the µC to fetch instructions using only the
upper eight data bits. The boot ROM checks the system
and waits for commands from the host. Refer to the EV
kit manual for specific start-up procedures.
All software is supplied on a disk with the EV kit.
Instructions for operating the software are included in
the EV kit manual. Refer to the EV kit manual for more
information.
Use the 68HC16MOD-16WIDE module only with those
EV kits that are designed to support it, and only down-
load code that is targeted for the 68HC16MOD-16WIDE
module. Downloading incorrect object code into the
68HC16MOD-16WIDE module will have unpredictable
results.
Table 1. Serial Communications Port J3
PIN
1
2
3
4
5
6
7
8
9
NAME
None
GND
DCD
RXD
TXD
DTR
DSR
CTS
RTS
Handshake; hard-wired to DTR and DSR
RS-232-compatible data output from
68HC16MOD-16WIDE module
RS-232-compatible data input to
68HC16MOD-16WIDE module
Handshake; hard-wired to DCD and DSR
Signal ground connection
Handshake; hard-wired to DCD and DTR
Handshake; hard-wired to CTS
Handshake; hard-wired to RTS
Unused
FUNCTION
Boot ROM
Software