CS5535-UDCF AMD (ADVANCED MICRO DEVICES), CS5535-UDCF Datasheet - Page 122

• Manufacturer Part Number: CS5535-UDCF
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of CS5535-UDCF

• Operating Temperature (min): 0C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

5.10
The Keyboard Emulation Logic (KEL) provides a virtual
8042 keyboard controller interface that is used to map non-
legacy keyboard and mouse sources to this traditional
interface. For example, Universal Serial Bus (USB)
sources are “connected” to this interface via System Man-
agement Mode (SMM) software. It also allows mixed envi-
ronments with one LPC legacy device and multiple new
(USB) devices. It produces IRQ and ASMI outputs.
Features
• Provides a virtual 8042 keyboard controller interface.
• Allows mixed environments.
122
14 MHz
14 MHz
1 kHz
Local Bus Data
to
Keyboard Emulation Logic
IN
32
*
*
*
*
*
OUT
Local Bus Clock
USB1_SOF
LPC_IRQ12
USB2_SOF
32
LPC_IRQ1
31506B
Reset
Control
Control
Output
KEL X
Status
1 kHz Clock
Input
HCE
HCE
HCE
HCE
Figure 5-22. KEL Block Diagram
* Read-Back Multiplexer is not shown
Logic (KEL)
Keyboard
Emulator
• Produces IRQ and ASMI outputs.
• Employs a clock control logic for power management
• No USB controller required for KEL to operate.
5.10.1
The Keyboard Emulation Logic (KEL) with Port A is illus-
trated in Figure 5-22. Strictly speaking, these are separate
functions. However, since they both effect the FA20#
(Force processor Address bit 20 to zero when low), the two
functions are implemented together. The Keyboard Emula-
tion Logic is the most complex and is discussed first.
purposes.
AMD Geode™ CS5535 Companion Device Data Book
Keyboard Emulation and Port A
Port 064h Write
Port 060h and
Port A Write
Port 060h
Port 064h
& Read
Read
Read
IRQ 1 (to PIC Subsystem)
IRQ 12 (to PIC Subsystem)
EmulationInterrupt
ASMI
EmulationEnable
SnoopEnable
FA20#
INIT Keyboard
A20 Keyboard
INIT Port A
A20 Port A
Port A Enable
Keyboard Emulation Logic
Local Bus Data
OUT
*
*
8
IN
8