[wiki:Component SocLib Components General Index] 

= !VciMultiTty =

== 1) Functional Description ==

This VCI target is a TTY terminal controller. This hardware component controls
one or several independant terminals. The number of emulated
terminals is defined by the arguments in the constructor (one name per terminal).

Each terminal is acting both as a character display, and a keyboard interface.
For each terminal, a specific IRQ is activated when a character entered at the
keyboard is available in a buffer. IRQ is kept low as long as the buffer is not empty.

This hardware component cheks for segmentation violation, and can be used
as a default target.

This component uses a [wiki:Component/TtyWrapper TtyWrapper] per terminal in order to
abstract the simulated ttys. The terminal index ''i'' is defined by the ADDRESS![12:4] bits.

Each TTY controller contains 3 memory mapped registers:

 * `TTY_WRITE`
This 8 bits pseudo-register is write only.
Any write request will interpret the 8 LSB bits of the WDATA field
as an ASCII character, and this character will be displayed on the addressed terminal. 

 * `TTY_STATUS`
This Boolean status register is read-only. 
A read request returns the zero value if there is no pending character.
It returns a non zero value if there is a pending character in the keyboard buffer. 

 * `TTY_READ`
This 8 bits register contains one single ASCII character. 
This register is read-only. A read request returns the ACSII character
in the 8 LSB bits of the RDATA field, and reset the status register.

For extensibility issues, you should access your terminal using globally-defined offsets.

You should include file `soclib/tty.h` in your software, it
defines `TTY_WRITE`, `TTY_STATUS`, `TTY_READ` and `TTY_SPAN`.

A putc/getc implementation could be:
{{{
#include "soclib/tty.h"

static const volatile void* tty_address = 0xc0000000;

static inline void putc(const size_t term_no, const char x)
{
    soclib_io_set( tty_address, term_no*TTY_SPAN + TTY_WRITE, x );
}

static inline char getc(const size_t term_no)
{
    return soclib_io_get( tty_address, term_no*TTY_SPAN + TTY_READ );
}
}}}

(add -I/path/to/soclib/include to your compilation command-line)

== 2) Component definition & usage ==

source:trunk/soclib/soclib/module/connectivity_component/vci_multi_tty/caba/metadata/vci_multi_tty.sd

See [wiki:SoclibCc/VciParameters SoclibCc/VciParameters]
{{{
Uses( 'vci_multi_tty', **vci_parameters )
}}}

== 3) CABA  Implementation ==
 
=== CABA sources ===
  
 * interface : source:trunk/soclib/soclib/module/connectivity_component/vci_multi_tty/caba/source/include/vci_multi_tty.h
 * implementation : source:trunk/soclib/soclib/module/connectivity_component/vci_multi_tty/caba/source/src/vci_multi_tty.cpp


=== CABA Constructor parameters ===

{{{
VciMultiTty(
     sc_module_name name,   // Instance name
     const soclib::common::IntTab &index,   //  Target index
     const soclib::common::MappingTable &mt,   // Mapping Table
     const char *first_tty_name, ...);   // TTY names (as many names as terminals)
}}}

Example instanciation:
{{{
VciMultiTty  tty("tty_comp", 
               IntTab(2,3), 
               mapping_table, 
              "term0", "term1", "term2", NULL);
}}}
Note : the name list MUST be terminated by NULL.

=== CABA Ports ===

 * sc_in<bool> '''p_resetn''' : Global system reset
 * sc_in<bool> '''p_clk''' : Global system clock
 * soclib::common::!VciiTarget<vci_param> '''p_vci''' : The VCI port
 * sc_out<bool> '''p_irq[]''' : Interrupt ports array.

== 4) TLM-T Implementation ==

=== TLM-T sources ===

 * interface : source:trunk/soclib/soclib/module/connectivity_component/vci_multi_tty/tlmt/source/include/vci_multi_tty.h
 * implementation : source:trunk/soclib/soclib/module/connectivity_component/vci_multi_tty/tlmt/source/src/vci_multi_tty.cpp

=== TLM-T Constructor parameters ===
{{{
VciMultiTty(
     sc_module_name name,                      // Instance name
     const soclib::common::IntTab &index,      // Target index
     const soclib::common::MappingTable &mt,   // Mapping Table
     const char *first_tty_name, ...);         // TTY names (as many names as terminals)
}}}

=== TLM-T Ports ===

 * soclib::tlmt::!VciTarget<vci_param> '''p_vci''' : The VCI port
 * std::vector<tlmt_core::tlmt_out<bool> *> '''p_irq''' : Interrupts ports array