CD2401 Intel, CD2401 Datasheet - Page 155

• Manufacturer Part Number: CD2401
• Description: Multi-protocol Communications Controller
• Manufacturer: Intel

8.7.3.2
8.7.4
Datasheet
Register Name: GT1h
Register Description: General Timer 1 – high byte
Default Value: x’00
Access: Byte Read/Write
Register Name: GT2
Register Description: General Timer 2
Default Value: x’00
Access: Byte Read/Write
Bit 15
Bit 7
General Timer 1 – High (GT1h) – Sync Modes only
This 16-bit timer can be started by the user whenever it is inactive by writing a 16-bit timeout value
to this register. When this register is non-zero, it decrements on each prescaler clock ‘tick’. When it
reaches zero, a modem/timer group interrupt is generated to the host. The timer can be disabled by
a CCR command. In addition, during an interrupt the user can reload a running timer (high byte
only) by providing a reload value in the Interrupt Status register, and a reload timer command in
the End of Interrupt register for the interrupt being serviced. In a single-interrupt routine, only one
general timer can be restarted this way.
General Timer 2 (GT2) Register — Sync Modes only
This 8-bit timer can be started by the user whenever it is inactive by writing an 8-bit timeout value
to the timer register. When this register is non-zero, it decrements on each prescaler clock ‘tick’.
When it reaches zero, a modem/timer group interrupt is generated to the host. The timer can be
disabled by a CCR command if the timer’s current value is greater than ‘1’. In addition, during a
receive or transmit interrupt, the user can reload a running timer by providing a reload value in the
Interrupt Status register and a reload timer command in the End of Interrupt register for the
interrupt being serviced. In a single-interrupt routine, only one general timer can be restarted this
way.
Bit 14
Bit 6
Bit 13
Bit 5
Bit 12
Bit 4
Multi-Protocol Communications Controller — CD2401
Binary Value
Binary Value
Bit 11
Bit 3
Bit 10
Bit 2
Motorola Hex Address: x’2A
Motorola Hex Address: x’29
Bit 9
Bit 1
Intel Hex Address: x’2A
Intel Hex Address: x’29
Bit 8
Bit 0
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