Difference between revisions of "IOP16 PS/2 Keyboard"
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* Blocking routine waits for keypress | * Blocking routine waits for keypress | ||
− | * Returns ASCII key value in | + | * Returns ASCII key value in Reg1 |
<pre> | <pre> | ||
RDKBD JSR WTKBRX WAIT FOR KBD RX CHAR | RDKBD JSR WTKBRX WAIT FOR KBD RX CHAR | ||
− | IOR | + | IOR 0X01 0X0D READ KBD CHAR |
RTS | RTS | ||
− | WTKBRX IOR | + | WTKBRX IOR 0X01 0X0C READ KBD STATUS |
− | ARI | + | ARI 0X01 0X01 RX RDY BIT |
BEZ WTKBRX LOOP UNTIL CHAR PRESENT | BEZ WTKBRX LOOP UNTIL CHAR PRESENT | ||
</pre> | </pre> | ||
Line 35: | Line 35: | ||
=== Poll the keyboard === | === Poll the keyboard === | ||
− | * Returns 0x00 = No key | + | * Returns keyboard status in Reg1 |
− | * Returns 0x01 - Key was pressed | + | ** Returns 0x00 = No key |
+ | ** Returns 0x01 - Key was pressed | ||
<pre> | <pre> | ||
− | POLLKBD IOR | + | POLLKBD IOR 0X01 0X0C |
RTS | RTS | ||
</pre> | </pre> |
Latest revision as of 17:59, 16 April 2022
Contents
PS/2 Keyboard
- Wrapper for PS/2 keyboard interfaces
- PS/2 to ASCII conversion
Software Interface
Status register (Read only)
- Addr = 0
- Value = 0x00, No data present
- Value = 0x01, Data present
Data register (Read only)
- Addr = 1
- ASCII Data
PS/2 Keyboard Subroutines
Get character from keyboard
- Blocking routine waits for keypress
- Returns ASCII key value in Reg1
RDKBD JSR WTKBRX WAIT FOR KBD RX CHAR IOR 0X01 0X0D READ KBD CHAR RTS WTKBRX IOR 0X01 0X0C READ KBD STATUS ARI 0X01 0X01 RX RDY BIT BEZ WTKBRX LOOP UNTIL CHAR PRESENT
Poll the keyboard
- Returns keyboard status in Reg1
- Returns 0x00 = No key
- Returns 0x01 - Key was pressed
POLLKBD IOR 0X01 0X0C RTS
Hook-up
- Add to Top Level VHDL code
Pins
- Add to top level entity pins list
-- PS/2 ps2Clk : inout std_logic; ps2Data : inout std_logic;
Signals
- Add signal into architecture section
-- Decodes/Strobes ... signal w_kbcs : std_logic; -- Interfaces ... signal w_KbdData : std_logic_vector(7 downto 0);
VHDL Instance
-- PS/2 keyboard/mapper to ANSI KEYBOARD : ENTITY WORK.Wrap_Keyboard port MAP ( i_CLOCK_50 => i_clk, i_n_reset => w_resetClean_n, i_kbCS => w_kbcs, i_RegSel => w_periphAdr(0), i_rd_Kbd => w_kbcs, i_ps2_clk => ps2Clk, i_ps2_data => ps2Data, o_kbdDat => w_KbdData );
Hook-up Strobes/Read Mux
- Add to strobes and read mux
-- Strobes/Selects ... w_kbcs <= '1' when (w_periphAdr(7 downto 1) = "0000110") and (w_periphRd = '1') else '0'; -- Peripheral bus read mux w_periphIn <= ... w_KbdData when w_periphAdr(7 downto 1) = "0000110" else ...
Resources
- Logic Cells: 708
- Registers: 95
- Memory Bits: 0
- M9Ks: 0