6f7cb9978b
Separating units from value Khz -> kHz More on units, ohm -> Ω More changes performed while translating More changes performed while translating Requested changes during peer review
62 lines
2.7 KiB
Text
62 lines
2.7 KiB
Text
\# Author Andy Pugh
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\# Issued under the terms of the GPL v2 License or any later version
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.TH hm2_uart_setup "3hm2" "2011-05-31" "LinuxCNC Documentation" "Hostmot2"
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.SH NAME
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hm2_uart_setup \- setup a Hostmot2 UART
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.SH SYNTAX
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.nf
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.B #include <hostmot2-serial.h>
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.HP
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int hm2_uart_setup(char *name, int bitrate, s32 tx_mode, s32 rx_mode){
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.SH DESCRIPTION
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\fBhm2_uart_setup\fR Setup the bitrate for the UART named "name".
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"name" is a unique string given to each UART during hostmot2
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setup. The names of the available UARTs are printed to standard output during
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the driver loading process and take the form:
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hm2_<board name>.<board index>.uart.<index> For example hm2_5i23.0.uart.0
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The minimum bitrate is approximately 50bps, and the maximum around the FPGA
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frequency, 48 MHz for a 5i23.
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The UART function allows different RX and TX bitrates, but that is not currently
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supported by this driver
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tx_mode is bit mask defined in the Hostmot2 regmap:
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Bit 0..3 = TXEnable delay. TXEnable delay specifies the transmit data
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holdoff time from the TXenable signal valid state. This is used for
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RS-485 (half duplex) operation, to delay transmit data until the driver
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is enabled, allowing for driver enable delays, isolation barrier delays
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etc. Delay is in units of ClockLow period.
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Bit 4 = FIFOError, it indicates that a host push has overflowed the FIFO
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(Mainly for driver debugging)
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Bit 5 = DriveEnableAuto, When set, enables Drive when any data is in FIFO or
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Xmit Shift register,removes drive when FIFO and Xmit shift register
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are empty.
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Bit 6 = DriveEnableBit, If DriveEnableAuto is 0, controls Drive (
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for software control of Xmit drive)
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rx_mode is bit mask defined in the Hostmot2 regmap:
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Bit 0 = FalseStart bit Status, 1 = false start bit detected
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Bit 1 = OverRun Status, 1 = overrun condition detected (no valid stop bit)
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Bit 2 = RXMaskEnable, 1= enable RXMask for half duplex operation,
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0 = ignore RXMask
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Bit 4 = FIFOError, indicates that a host read has attempted to read more
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data than available. (mainly for driver debugging)
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Bit 5 = LostDataError, indicates that data was received with no room in FIFO,
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therefore lost
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Bit 6 = RXMask, RO RXMASK status
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Bit 7 = FIFO Has Data
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rx_mode and tx_mode registers are currently write-only. There should possibly be
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a get-status function.
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To write only to the tx_mode DriveEnable bit call this function with the bitrate
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unchanged and \-1 as the rx_mode
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To change bitrate without altering mode settings send \-1 to both modes.
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.SH RETURN VALUE
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Returns0 on success and \-1 on failure
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.SH SEE ALSO
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man hm2_uart_send, man hm2_uart_read
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See src/hal/drivers mesa_uart.comp for an example usage.
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