Maxim Integrated 73M1822/73M1922 Control Module - Manual (Page 35)

UG_1x22_053 73M1822/73M1922 Control Module User Guide
Rev. 1.0 35
6.3 Modem Hook Switch Control Services
The configuration and control of the modem Hook Switch is accomplished by using the IOCTLs
summarized in Table 3.
Table 3: Modem Hook Switch Control Services
Events and Status Description Descriptor
M1X22_ENNOM_DELAY_TIMER Allows the developer to tune the EnNom response
timer.
Channel
M1X22_ATH1 Issue off-hook in the modem interface. Channel
M1X22_ATH0 Issue on-hook in the modem interface. Channel
M1X22_ATDP Pulse dial. Channel
M1X22_ATDP_CANCEL Pulse dial abort or cancel. Channel
M1X22_ATDP_PARAM Pulse dial parameters. Channel
M1X22_FLSH_CFG Configure of flash-hook parameter for the modem
interface. Channel
M1X22_FLSH_SET Perform hook flashing on the modem interface. Channel
M1X22_SEND_WETTING_PULSE Perform a wetting pulse on the modem interface. Channel
6.3.1 M1X22_ENNOM_DELAY_TIMER
This IOCTL allows an application program to change the ENNOM delay timer from the default value of
350 ms to any value within the valid ranges of 10 to 350 ms, inclusive
Description
Delaying of ENNOM bit setting is required for loop stabilization during off hook operation. However, the
duration depends largely on the quality of the hook circuit design. The driver uses the default setting of
350 ms an optimized choice for response time and audio quality. This IOCTL allows developers to tune
this timing value to suit their specific needs.
#define M1X22_ENNOM_DELAY_TIMER _IOWR(0xA4, 0xF8, unsigned int)
Prototype
int ioctl (
int chan_fd,
int M1X22_ENNOM_DELAY_TIMER,
unsigned long param );
Parameters
Data Type Name Description
int chan_fd Channel descriptor.
int M1X22_ENNOM_DELAY_TIMER I/O control identifier for this operation.
unsigned long param The desired ENNOM delay duration.
Range from 10 to 350 ms, inclusive.
Return Values
Data Type Description
int Always returns 0.