CD2481 Datasheet, PDF (181/222 Pages) Intel Corporation – Programmable Four-Channel Communications Controller

Programmable Four-Channel Communications Controller — CD2481
9.5.4.4
Bit 5
CTS changed
A logic ‘1’ indicates that a change has been detected on the CTS* input. The change
detect is programmed in COR4 and COR5.
Bits 4:2
Reserved; returns ‘0’ when read
Bit 1
General timer 2 timed out (count reaches zero before being reset or disabled).
Bit 0
General timer 1 timed out (count reaches zero before being reset or disabled).
During an interrupt service routine, the host can use this register to provide a binary timer value to
one of the timers (Sync modes only), as detailed in the Modem End of Interrupt register. The host
can only load one of the two timers in each interrupt service routine.
Modem End of Interrupt Register (MEOIR)
Register Name: MEOIR
Register Description: Modem End of Interrupt Register
Default Value: x’00
Access: Byte Write Only
Bit 7
Bit 6
Bit 5
Bit 4
0
0
SetTm2
SetTm1
Bit 3
0
Intel Hex Address: x’85
Motorola Hex Address: x’86
Bit 2
0
Bit 1
0
Bit 0
0
Bits 7:6
Bit 5
Bit 4
Bits 3:0
Reserved – must be zero.
Set general timer 2 (Synchronous modes only)
0 = do not set general timer 2.
1 = load the value, provided in MISR, to general timer 2.
Set general timer 1 (Synchronous modes only)
0 = do not set general timer 1.
1 = load the value, provided in MISR, to the high byte of general timer 1.
At the end of an interrupt service routine, the user can set the timer by setting a timer
value in the Modem Interrupt Status register. When the timer reaches ‘0’, the
CD2481 generates a modem/timer group interrupt to the host.
Reserved – must be zero.
Datasheet
181