Datasheet

Rev. J | Page 12 of 60 | July 2013
ADSP-21362/ADSP-21363/ADSP-21364/ADSP-21365/ADSP-21366
SPICLK I/O
(pu)
Three-state with
pull-up enabled,
driven high in SPI-
master boot mode
Serial Peripheral Interface Clock Signal. Driven by the master, this signal controls the
rate at which data is transferred. The master can transmit data at a variety of baud rates.
SPICLK cycles once for each bit transmitted. SPICLK is a gated clock active during data
transfers, only for the length of the transferred word. Slave devices ignore the serial clock
if the slave select input is driven inactive (high). SPICLK is used to shift out and shift in
the data driven on the MISO and MOSI lines. The data is always shifted out on one clock
edge and sampled on the opposite edge of the clock. Clock polarity and clock phase
relative to data are programmable into the SPICTL control register and define the transfer
format. SPICLK has a 22.5 kΩ internal pull-up resistor.
SPIDS
I Input only Serial Peripheral Interface Slave Device Select. An active low signal used to select the
processor as an SPI slave device. This input signal behaves like a chip select, and is
provided by the master device for the slave devices. In multimaster mode the processor’s
SPIDS
signal can be driven by a slave device to signal to the processor (as SPI master)
that an error has occurred, as some other device is also trying to be the master device. If
asserted low when the device is in master mode, it is considered a multimaster error. For
a single-master, multiple-slave configuration where flag pins are used, this pin must be
tied or pulled high to V
DDEXT
on the master device. For processor to processor SPI inter-
action, any of the master processor’s flag pins can be used to drive the SPIDS signal on
the SPI slave device.
MOSI I/O (O/D)
(pu)
Three-state with
pull-up enabled,
driven low in SPI-
master boot mode
SPI Master Out Slave In. If the ADSP-2136x is configured as a master, the MOSI pin
becomes a data transmit (output) pin, transmitting output data. If the processor is
configured as a slave, the MOSI pin becomes a data receive (input) pin, receiving input
data. In an SPI interconnection, the data is shifted out from the MOSI output pin of the
master and shifted into the MOSI input(s) of the slave(s). MOSI has a 22.5 kΩ internal pull-
up resistor.
MISO I/O (O/D)
(pu)
Three-state with
pull-up enabled
SPI Master In Slave Out. If the ADSP-2136x is configured as a master, the MISO pin
becomes a data receive (input) pin, receiving input data. If the processor is configured
as a slave, the MISO pin becomes a data transmit (output) pin, transmitting output data.
In an SPI interconnection, the data is shifted out from the MISO output pin of the slave
and shifted into the MISO input pin of the master. MISO has a 22.5 kΩ internal pull-up
resistor. MISO can be configured as O/D by setting the OPD bit in the SPICTL register.
Note: Only one slave is allowed to transmit data at any given time. To enable broadcast
transmission to multiple SPI slaves, the processor’s MISO pin can be disabled by setting
Bit 5 (DMISO) of the SPICTL register equal to 1.
CLKIN I Input only Local Clock In. Used in conjunction with XTAL. CLKIN is the ADSP-2136x clock input. It
configures the ADSP-2136x to use either its internal clock generator or an external clock
source. Connecting the necessary components to CLKIN and XTAL enables the internal
clock generator. Connecting the external clock to CLKIN while leaving XTAL uncon-
nected configures the processors to use the external clock source such as an external
clock oscillator. The core is clocked either by the PLL output or this clock input depending
on the CLK_CFG1–0 pin settings. CLKIN should not be halted, changed, or operated
below the specified frequency.
XTAL O Output only
2
Crystal Oscillator Terminal. Used in conjunction with CLKIN to drive an external crystal.
CLK_CFG1–0 I Input only Core to CLKIN Ratio Control. These pins set the start up clock frequency. Note that the
operating frequency can be changed by programming the PLL multiplier and divider in
the PMCTL register at any time after the core comes out of reset. The allowed values are:
00 = 6:1
01 = 32:1
10 = 16:1
11 = reserved.
Table 6. Pin Descriptions (Continued)
Pin Type
State During and
After Reset Function
The following symbols appear in the Type column of Table 6: A = asynchronous, G = ground, I = input, O = output, P = power supply,
S = synchronous, (A/D) = active drive, (O/D) = open drain, and T = three-state, (pd) = pull-down resistor, (pu) = pull-up resistor.