Changes between Version 3 and Version 4 of Component/Vci Multi Tty

Timestamp:

May 9, 2007, 2:46:35 PM (17 years ago)

Author:

Nicolas Pouillon

Comment:

--

Component/Vci Multi Tty

@@ -4 +4 @@
 
 This VCI target is a TTY terminal controller. This hardware component controls
-up to 256 terminals, emulated as XTERM windows. The number of emulated
-terminals is defined by the arguments in the constructor.
-The constructor creates as many UNIX XTERM processes as the number N of emulated terminals.
-It creates N PTY pseudo-terminals (one for each XTERM process), to support the bidirectional
-communication between the TTY controller process and the XTERM processes. 
+independant terminals. The number of emulated
+terminals is defined by the arguments in the constructor (one name per terminal).
+Name list MUST be terminated by NULL.
+
 Each terminal is acting both as a character display, and a keyboard interface.
-For each terminal, a specific IRQ is activated when a character is entered at the keyboard. 
-The terminal index i is defined by the ADDRESS![12:4] bits.
-The address space segment allocated to this component must be aligned
-on a 4K bytes boundary.
+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 different simulator's ttys.
+
+= Memory region layout =
+
+The terminal index ''i'' is defined by the ADDRESS![12:4] bits.
+
 Each TTY controller contains 3 memory mapped registers:
 
- * '''TTY_DISPLAY'''     : ADDRESS![3:0] = 0x0
+ * `TTY_WRITE`: ADDRESS![3:0] = 0x0
 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_KEY_STS''' : ADDRESS![3:0] = 0x4 
+ * `TTY_STATUS`: ADDRESS![3:0] = 0x4 
 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_KEY_BUF'''    : ADDRESS![3:0] = 0x8
+ * `TTY_READ`: ADDRESS![3:0] = 0x8
 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
+
+= Component usage =
+
+For extensibility issues, you should access your terminal using globally-defined offsets.
+
+You should include file source:trunk/soclib/include/soclib/tty.h from 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)
+{
+    volatile int *tty = ((int*)tty_address) + term_no*TTY_SPAN;
+    tty[TTY_WRITE] = x;
+}
+
+static inline char getc(const size_t term_no)
+{
+    volatile int *tty = ((int*)tty_address) + term_no*TTY_SPAN;
+    return tty[TTY_READ];
+}
+}}}
+
+(add -I/path/to/soclib/include to your compilation command-line)
 
 = !VciMultiTty CABA  Implementation =
@@ -44 +77 @@
 
 == Constructor parameters ==
+
 {{{
 VciMultiTty(
@@ -53 +87 @@
 }}}
 
+Example instanciation:
+{{{
+VciMultiTty tty("tty_comp", IntTab(2,3), mapping_table, "term0", "term1", "term2", NULL);
+}}}
+
 == Ports ==
 
@@ -58 +97 @@
  * sc_in<bool> '''p_clk''' : Global system clock
  * soclib::common::!VciiTarget<vci_param> '''p_vci''' : The VCI port
- * sc_out<bool> '''*p_irq''' : Pointer on the interrupt ports array.
+ * sc_out<bool> '''p_irq[]''' : Interrupt ports array.