Rainbow Electronics MAX1289 - Manual (Page 11)

edges. DOUT transitions on SCLK’s falling edge
and is available in MSB-first format. Observe the
SCLK to DOUT valid timing characteristic. Clock
data into the µP on SCLK’s rising edge.
SPI and MICROWIRE Interface
When using an SPI (Figure 8a) or MICROWIRE inter-
face (Figures 8a and 8b), set CPOL = CPHA = 0. Two
8-bit readings are necessary to obtain the entire 12-bit
result from the ADC. DOUT data transitions on the seri-
al clock’s falling edge and is clocked into the µP on
SCLK’s rising edge. The first 8-bit data stream contains
the first 8-bits of DOUT starting with the MSB. The sec-
ond 8-bit data stream contains the remaining four result
bits. DOUT then goes high impedance.
QSPI Interface
Using the high-speed QSPI interface (Figure 9a) with
CPOL = 0 and CPHA = 0, the MAX1286–MAX1289
support a maximum f
SCLK of 8MHz. One 12- to 16-bit
reading is necessary to obtain the entire 12-bit result
from the ADC. DOUT data transitions on the serial
clock’s falling edge and is clocked into the µP on
SCLK’s rising edge. The first 12 bits are the data.
DOUT then goes high impedance (Figure 9b).
PIC16 and SSP Module and
PIC17 Interface
The MAX1286–MAX1289 are compatible with a
PIC16/PIC17 µC, using the synchronous serial port
(SSP) module
To establish SPI communication, connect the controller
as shown in Figure 10a and configure the PIC16/PIC17
as system master. This is done by initializing its syn-
chronous serial port control register (SSPCON) and
synchronous serial port status register (SSPSTAT) to
the bit patterns shown in Tables 1 and 2.
In SPI mode, the PIC16/PIC17 µCs allow 8 bits of data
to be synchronously transmitted and received simulta-
neously. Two consecutive 8-bit readings (Figure 10b)
are necessary to obtain the entire 12-bit result from the
ADC. DOUT data transitions on the serial clock’s falling
edge and is clocked into the µC on SCLK’s rising edge.
The first 8-bit data stream contains the first 8 data bits
starting with the MSB. The second data stream con-
tains the remaining bits, D3 through D0.
MAX1286–MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
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Figure 8a. SPI Connections Figure 8b. MICROWIRE Connections
CNVST
SCLK
DOUT
I/O
SCK
MISO
V DD
SS
SPI
MAX1286–
MAX1289
MAX1286–
MAX1289
CNVST
SCLK
DOUT
I/O
SK
SI
MICROWIRE
Table 1. Detailed SSPCON Register Content
CONTROL BIT
MAX1286–MAX1289
SETTINGS
SYNCHRONOUS SERIAL PORT CONTROL REGISTER (SSPCON)
WCOL Bit 7 X Write Collision Detection Bit
SSPOV Bit 6 X Receive Overflow Detect Bit
SSPEN Bit 5 1
Synchronous Serial Port Enable Bit:
0: Disables serial port and configures these pins as I/O port pins.
1: E nab l es ser i al p or t and confi g ur es S C K, S D O, and S C I p i ns as ser i al p or t p i ns.
CKP Bit 4 0 Clock Polarity Select Bit. CKP = 0 for SPI master mode selection.
SSPM3 Bit 3 0
SSPM2 Bit 2 0
SSPM1 Bit 1 0
SSPM0 Bit 0 1
Synchronous Serial Port Mode Select Bit. Sets SPI master mode and selects
F
CLK = f OSC / 16.