% render "layouts/basic.html" do

%# HTML tags can be embedded in mark down files if you want to do specific custom
%# formatting like this, but in most cases that is not required.
<h1><%= Origen.app.namespace %> <span style="font-size: 14px">(<%= Origen.app.version %>)</span></h1>

### Purpose

This plugin implements SPI protocol with the tester acting as the master. There are 4 pins standard to SPI, 
however only sclk is required by this plugin. Any pins that aren't provided are ignored. This plugin seeks
to be very flexible given that the SPI standard is itself very flexible.

### How To Install

In your Gemfile add:

~~~ruby
gem "<%= Origen.app.name %>"
~~~

or if your application is a plugin, then add this to your <code>.gemspec</code>

~~~ruby
spec.add_runtime_dependency "<%= Origen.app.name %>", ">= <%= Origen.app.version %>"
~~~

__NOTE:__  In the case of a plugin, you will also need to <code>require '<%= Origen.app.name %>'</code> somewhere in your environment.


### How To Use

The spi driver is intended to be instantiated as a sub_block. The configuration can be passed in as a hash and / or 
can be changed after instantiation. See API for more details.

~~~ruby
        sub_block :spi, class_name:   'OrigenSpi::Driver',
                        sclk_pin:     dut.pin(:sclk),
                        mosi_pin:     dut.pin(:mosi),
                        miso_pin:     dut.pin(:miso),
                        ss_pin:       dut.pin(:ss),
                        # :rl - return low - input data changes while sclk is low and is latched on rising edge
                        clk_format:   :rl,
                        # drive state of 0 activates the slave port
                        ss_active:    0,
                        # wait time after ss_active and before any sclk activity
                        clk_wait_time: {time_in_cycles: 2},
                        # number of sclks per tester.cycle
                        clk_multiple: 1,
                        data_order:   :lsb0
~~~

~~~ruby
  # configuration can be changed after instantiation like this
  dut.spi.clk_multiple = 80
  dut.spi.miso_compare_cycle = 79
  dut.spi.ss_pin = nil
~~~

Once the driver is instantiated shift operations can be performed by calls to the shift method (overlay/store/masking etc. is handled):

~~~ruby
  # shift out, masking input compares
  dut.spi.shift master_out: 0xFF, size: 32
  
  # shift out, register - size doesn't need to be passed when register is provided
  dut.spi.shift master_out: dut.my_reg
  
  # shift in read examples:
  dut.spi.shift master_in: 0xFF, size: 32
  
  # provide a register to mask or store (mark the bits appropriately)
  dut.spi.shift master_in: dut.my_reg
  
  # simultaneous shift in/out
  dut.spi.shift master_out: some_value_or_reg, master_in: some_other_value_or_reg
~~~


### How To Setup a Development Environment

To setup a development environment:

~~~
  git clone https://github.com/Origen-SDK/origen_spi.git
~~~

% end