PS2 interface
Introduction
J Class implements the keyboard and mouse interfaces as simple serial ports conforming to the de facto
industry standard PS/2 specification. Each user input device has a dedicated serial port of its own. LASI
includes two ports, one for keyboard and one for mouse. The interface ports rely on the software to
provide all of their intelligence. Therefore, they do not interpret the characters passing through them in
either direction. The interface to the host processor is through 6 one–byte registers for each port.
Registers
Table 4–4 shows the PS/2 interface registers.
Table 4–4. PS/2 Interface Registers
Register
Label
Register Name
Address offset
(word
aligned)
Reset
Value
Access
ID
ID Register
0x00
note 1
R
RESET
Interface reset register
0x00
0xXX
W
RCVDATA
Received data register
0x04
0xXX
R
XMTDATA
Transmit data register
0x04
0xXX
W
CONTROL
Control register––read/write
0x08
0x00
note 2
R/W
STATUS
Status register––read only
0x0c
0x00
R
Note 1: Each PS2 device returns a unique hardwired ID code in bits 3:0 of ID.
Note 2: Resetting the block disables it.
ID Register
Table 4–5 shows the PS/2 ID register.
Table 4–5. PS/2 ID Register
Bit
Symbol
Name
Description
3:0
ID
ID Code
Hardwired physical identification bits. (0=key-
board;1=mouse)
7:4
Reserved
Reset Register
Any write to this register will cause the interface to be reset: all buffers will be emptied and the
receive/transmit state machines will be reset. The value of the data written will be discarded. Note that
this does not cause the external device to be reset; it must be reset explicitly through a command sent from
the host. A reset will leave the interface in the disabled state.
Содержание Visualize J200
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Страница 76: ... 1 1 0 2 1 1 0 2 0 0 3 Figure 6 4 Package Pallet ...
Страница 82: ... Figure 8 1 Danish Keyboard ...
Страница 83: ... Figure 8 2 French Keyboard ...
Страница 84: ... Figure 8 3 German Keyboard ...
Страница 85: ... Figure 8 4 Italian Keyboard ...
Страница 86: ... Figure 8 5 Japanese Keyboard ...
Страница 87: ... Figure 8 6 Korean Keyboard ...
Страница 88: ... Figure 8 7 Norwegian Keyboard ...
Страница 89: ... Figure 8 8 Spanish Keyboard ...
Страница 90: ...8 10 Keyboard Layouts J Class Technical Reference Figure 8 9 Swedish Keyboard ...
Страница 91: ... Figure 8 10 Swiss Keyboard ...
Страница 92: ...8 12 Keyboard Layouts J Class Technical Reference Figure 8 11 Taiwanese Keyboard ...
Страница 93: ...8 13 J Class Technical Reference Keyboard Layouts Figure 8 12 United Kingdom Keyboard ...
Страница 94: ...8 14 Keyboard Layouts J Class Technical Reference Figure 8 13 United States Keyboard ...