Digi NS9750 - Manual (Page 655)

w w w . d i g i e m b e d d e d . c o m 6 3 1
S e r i a l C o n t r o l M o d u l e : U A R T
Register bit assignment
Bits Access Mnemonic Reset Description
D31 R/W TRUN 0 Buffer GAP timer enable
0 Disables the timer
1 Enables the timer
D30:16 R/W Not used 0x0000 Must be written as 0.
D15:00 R/W BT 0x0000 Buffer GAP timer
Defines the required value for the receive buffer GAP
timer. BT is a function of the channel bit-rate and the
receive buffer size.
Recommended approach: Set the buffer GAP timer to
be a value that is slightly larger than the amount of time
required to fill the maximum buffer size using the channel
bit-rate. Compute the BT value as shown:
BT = (((Timeout * F
CLK
) / 512) - 1)
where:
F
CLK
= (x1_sys_osc / M ) (see Table 364 for examples)
Timeout = Appropriate timeout in seconds
Use the following equation to define the recommended
buffer GAP timeout value.
Timeout = (((BufferSize + 1) * 8) / DataRate)
where:
BufferSize = receive buffer size in bytes
DataRate = interface data rate in bits
Table 374: Serial Channel B/A/C/D Receive Buffer GAP Timer