Datasheet

© 2011 Microchip Technology Inc. DS25048B-page 31
MCP3903
FIGURE 6-2: Device Read (SPI MODE 0,0 - Clock Idles Low).
FIGURE 6-3: Device Write (SPI Mode 0,0 - Clock Idles Low).
6.6 SPI MODE 1,1 - Clock Idle High,
Read/Write Examples
In this SPI mode, the clock idles High. For the
MCP3903, this means that there will be a falling edge
before there is a rising edge.
FIGURE 6-4: Device Read (SPI Mode 1,1 - Clock Idles High).
SCK
SDI
SDO
CS
R/W
A6
A5
A4
A3
A2
A1
A0
D23
22
21
20
19
18
17
16
(ADDRESS) 24 BIT DATA
D15 06
05
04
03
02
01
DATA TRANSITIONS ON
THE FALLING EDGE
MCU AND MCP3901 LATCH
BITS ON THE RISING EDGE
00
D23 (OF ADDRESS + 1 DATA)
HI-Z
HI-Z
HI-Z
D07
1 32
Note:
SCK
SDI
SDO
CS
R/W
A6
A5
A4
A3
A2
A1
A0
D23
22
21
20
19
18
17
D15
(ADDRESS) DATA
D6
D5
D4
D3
D2
D1
D23 OF (ADDRESS + 1) DATA
16
DATA TRANSITIONS ON
THE FALLING EDGE
MCU AND MCP3901 LATCH
BITS ON THE RISING EDGE
D0
HI-Z
HI-Z
HI-Z
D7
1
32
SCK
SDI
SDO
CS
A6
A5
A4
A3
A2
A1
A0
22
21
20
19
18
17
D8
(ADDRESS) DATA
D6
D5
D4
D3
D2
D1
DATA TRANSITIONS ON
THE FALLING EDGE
MCU AND MCP3901 LATCH
BITS ON THE RISING EDGE
D0
HI-Z
HI-Z
23
D7
R/W
HI-Z
D16
1
32