Cirrus Logic CS5461A - Manual (Page 23)

CS5461A
DS661F3 23
5.14 Commands
All commands are 8-bits in length. Any byte that is not listed in this section is invalid. Commands that write to regis-
ters must be followed by 3 bytes of data. Commands that read data can be chained with other commands (e.g., while
reading data, a new command can be sent which can execute during the original read). All commands except reg-
ister reads, register writes, and SYNC0 & SYNC1 will abort any currently executing commands.
5.14.1 Start Conversions
Initiates acquiring measurements and calculating results. The device has three modes of acquisition.
C[3:2] Modes of acquisition/measurement
00 = Perform a single computation cycle
01 = Not Used
10 = Perform continuous computation cycles
11 = Perform continuous computation cycles with APF enabled on the other channel
5.14.2 SYNC0 and SYNC1
The serial port can be initialized by asserting CS or by sending three or more consecutive SYNC1 commands fol-
lowed by a SYNC0 command. The SYNC0 or SYNC1 can also be sent while sending data out.
SYNC 0 = Last byte of a serial port re-initialization sequence.
1 = Used during reads and serial port initialization.
5.14.3 Power-Up/Halt
If the device is powered-down, Power-Up/Halt will initiate a power on reset. If the part is already powered-on, all
computations will be halted.
5.14.4 Power-down and Software Reset
To conserve power the CS5461A has two power-down states. In stand-by state all circuitry, except the analog/digital
clock generators, is turned off. In the sleep state all circuitry, except the instruction decoder, is turned off. Bringing
the CS5461A out of sleep state requires more time than out of stand-by state, because of the extra time needed to
re-start and re-stabilize the analog oscillator.
S[1:0] Power-down state
00 = Software Reset
01 = Halt and enter stand-by power saving state. This state allows quick power-on
10 = Halt and enter sleep power saving state.
11 = Reserved
B7 B6 B5 B4 B3 B2 B1 B0
1 1 1 0 C3 C2 0 0
B7 B6 B5 B4 B3 B2 B1 B0
1 1 1 1 1 1 1 SYNC
B7 B6 B5 B4 B3 B2 B1 B0
1 0 1 0 0 0 0 0
B7 B6 B5 B4 B3 B2 B1 B0
1 0 0 S1 S0 0 0 0