Data Sheet
Pin No.
6, 10, 12, 16, 28, 32
40, 41, 42, 43
Mnemonic
NC
P0, P1, P2, P3
46
47
48
49
50
51, 52, 53
54
I/O_UPDATE
CS
SCLK
DVDD_I/O
SDIO_0
SDIO_1, SDIO_2,
SDIO_3
SYNC_CLK
AD9911
I/O Description
N/A No Connection. Analog Devices recommends leaving these pins floating.
I
These data pins are used for modulation (FSK, PSK, ASK), start/stop for the sweep
accumulator, and ramping up/down the output amplitude. Any toggle of these data
inputs is equivalent to an I/O_UPDATE. The data is synchronous to the SYNC_CLK (Pin
54). The data inputs must meet the set-up and hold time requirements to the
SYNC_CLK. This guarantees a fixed pipeline delay of data to the DAC output;
otherwise, a ±1 SYNC_CLK period of uncertainty occurs. The functionality of these
pins is controlled by profile pin configuration (PPC) bits in Register FR1 <12:14>.
I
A rising edge triggers data transfer from the I/O port buffer to active registers.
I/O_UPDATE is synchronous to the SYNC_CLK (Pin 54). I/O_UPDATE must meet the
set-up and hold time requirements to the SYNC_CLK to guarantee a fixed pipeline
delay of data to DAC output. If not, a ±1 SYNC_CLK period of uncertainty occurs. The
minimum pulse width is one SYNC_CLK period.
I
The active low chip select allows multiple devices to share a common I/O bus (SPI).
I
Data Clock for I/O Operations. Data bits are written on the rising edge of SCLK and
read on the falling edge of SCLK.
I
3.3 V Digital Power Supply for SPI Port and Digital I/O.
I/O Data pin SDIO_0 is dedicated to the I/O port only.
I/O Data pins SDIO_1:3 can be used for the I/O port or to initiate a ramp up/ramp down
(RU/RD) of the DAC output amplitude.
O
The SYNC_CLK, which runs at ¼ the system clock rate, can be disabled. I/O_UPDATE
and profile changes (Pin 40 to Pin 43) are synchronous to the SYNC_CLK. To guarantee
a fixed pipeline delay of data to DAC output, I/O_UPDATE and profile changes (Pin 40
to Pin 43) must meet the set-up and hold time requirements to the rising edge of
SYNC_CLK. If not, a ±1 SYNC_CLK period of uncertainty exists.
Rev. A | Page 11 of 41