IC-TW11 Datasheet, PDF (22/25 Pages) IC-Haus GmbH – 10-BIT ULTRA LOW POWER MAGNETIC ABSOLUTE ROTARY ENCODER

iC-TW11 10-BIT ULTRA LOW POWER^preliminary
MAGNETIC ABSOLUTE ROTARY ENCODER
BUSSING MULTIPLE ICs
Rev B1, Page 22/25
Multiple iC-TW11 slaves can be used with a single SPI gether and each device uses a separate slave select
host in a traditional SPI bus connection. In this case, (xSS) signal, as shown in Figure 9.
SCLK, SI, and SO on all devices are connected to-
Host µP
iC-TW11 3
xSS
SCLK
SI
V_IO
SO
IRQ_ IRQ_
IN OUT
iC-TW11 2
xSS
SCLK
SI
SO
IRQ_ IRQ_
IN OUT
iC-TW11 1
xSS
SCLK
SI
SO
IRQ_ IRQ_
IN OUT
xCS3
xCS2
xCS1
SCLK
MO
MI
IRQ
Figure 9: SPI bus connection of multiple iC-TW11s
In operation, the host initiates a sample of one of
the iC-TW11s by activating the appropriate chip se-
lect (xCS) and sending the appropriate read register
command. The host then either waits the appropriate
amount of time (see Figure 6 Page 17) or waits for
the interrupt request (IRQ) to be received to read the
sampled angle. In this case, the interrupt logic in all
iC-TW11s must be set to OR to ensure that the host
receives an interrupt request when any of the TW11
asserts its IRQ_OUT. This is accomplished by setting
the interrupt mode bit in the CONFIG register (CON-
FIG.imod = 1). See USING INTERRUPTS on Page 20
for more information.
Note that in a bussed configuration, only one iC-TW11
can be active at a time: the host must activate only one
chip select at a time. Because of this, simultaneous
sampling of multiple iC-TW11s in a bussed configura-
tion is only possible using the SAMPLE input.