XR18W750 ON Semiconductor, XR18W750 Datasheet - Page 32

• Manufacturer Part Number: XR18W750
• Manufacturer: ON Semiconductor

XR18W750
WIRELESS UART CONTROLLER
FCTR[3:2]: Reserved
For normal operation, these bits should be ’0’.
FCTR[5:4]: Transmit/Receive Trigger Table Select
See
FCTR[6]: Scratchpad Swap
•
•
FCTR[7]: Programmable Trigger Register Select
If using both programmable TX and RX trigger levels, TX trigger levels must be set before RX trigger levels.
•
•
EFR[3:0]: Reserved
For normal operation, these bits should be ’0’.
EFR[4]: Enhanced Function Bits Enable
Enhanced function control bit. This bit enables IER bits 4-7, ISR bits 4-5, FCR bits 4-5, and MCR bits 5-7 (MCR
bits 7-5 should remain at their default values of ’0’). After modifying any enhanced bits, EFR bit-4 can be set to
a logic 0 to latch the new values. This feature prevents legacy software from altering or overwriting the
enhanced functions once set. Normally, it is recommended to leave it enabled, logic 1.
•
•
EFR[5]: Reserved
For normal operation, this bit should be ’0’.
5.19
Logic 0 = Scratch Pad register is selected as general read and write register. ST16C550 compatible mode.
Logic 1 = FIFO Level Count register (Read-Only), Enhanced Mode Select Register (Write-Only). Number of
characters in transmit or receive FIFO can be read via scratch pad register when this bit is set. Enhanced
Mode Select Register is selected when it is written into.
Logic 0 = Registers TRG and FC selected for RX.
Logic 1 = Registers TRG and FC selected for TX.
Logic 0 = modification disable/latch enhanced features. IER bits 4-7, ISR bits 4-5, FCR bits 4-5, and MCR
bits 5-7are saved to retain the user settings. After a reset, the IER bits 4-7, ISR bits 4-5, FCR bits 4-5, and
MCR bits 5-7 are set to a logic 0 to be compatible with ST16C550 mode (default).
Logic 1 = Enables the above-mentioned register bits to be modified by the user.
Table 10
Enhanced Feature Register (EFR)
for more details.
FCTR
B
IT
0
0
1
1
-5
T
ABLE
FCTR
B
IT
0
1
0
1
-4
14: T
Table-A (TX/RX)
Table-B (TX/RX)
Table-C (TX/RX)
Table-D (TX/RX)
RIGGER
32
T
ABLE
T
ABLE
S
ELECT
REV. 1.0.0