Miscellaneous Registers
R/W
Index Mode Description
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-10h R/W IR Format Register (IRFMAT)
bit 7 = 1 invert sense of LED signal
= 0 normal sense of LED signal
bit 6 = 1 enable LED buffer empty interrupt
bit 5 = 1 LED buffer full (read only)
bit 4 = 0 single pulse transmission mode
= 1 multiple pulse transmission mode
bit 3 = 0 modulate using 32.768KHz
= 1 modulate using baud rate generator
bit 2 = 1 IR UART communication mode
bit 1 = 1 modulated communication mode
bit 0 = 1 REDEYE transmit mode
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-11h R/W IR Transmit / Receive Register
bit 7 state of the IRI pin (read only)
bit 6 = 1 enable IR interrupt on IRI = 1
bit 5 = 1 IR event has occurred, must be cleared by software
bits 4-3 unused
bit 2 = 1 gate output when in modulated communication mode
bit 1 = 0 transmit "off" half-bit in REDEYE format
= 1 transmit "on" half-bit in REDEYE format
bit 0 = 1 turn on LED driver, used for software controlled transmissions
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-12h R/W ADC Control Register
bits 7-5 unused except for testing
bit 4 = 1 ADC is busy doing a conversion; read only
bit 3 = 1 DAC value above analog input; read only (comparator output)
bits 2-1 input Voltage Channel Select, where:
= 00 system batteries
= 01 backup battery
= 10 reference voltage
= 11 VSS
bit 0 = 1 enable ADC
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-13h R/W ADC Value Register
bits 5-0 ADC value
bits 7-6 unused (read zero)
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-18h R/W First Byte of Interrupt Enable Register
bits 7-2 unused
bit 1 = 1 force PC Keyboard interrupt (IRQ1)
bit 0 = 1 enable timer 0 interrupt/wakeup (IRQ0)
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-19h R/W Second Byte of Interrupt Enable Register
bit 7 = 1 IR interrupt/wakeup (IRQ2)
bit 6 = 1 keyboard interrupt/wakeup (IRQ2)
bit 5 = 1 ring detect interrupt/wakeup (IRQ2)
bit 4 = 1 RX pad interrupt/wakeup (IRQ2)
bit 3 = 1 timer 1 interrupt/wakeup (IRQ2)
bit 2 = 1 RTC interrupt/wakeup (IRQ2)
bit 1 = 1 display cursor interrupt (IRQ2)
bit 0 = 1 low power interrupt (NMI)
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-1Ah R/W Interrupt Source Register
bit 7 = 1 IR interrupt (IRQ2)
bit 6 = 1 keyboard interrupt (IRQ2)
bit 5 = 1 ring detect interrupt (IRQ2)
bit 4 = 1 RX pad interrupt (IRQ2)
bit 3 = 1 timer 1 interrupt (IRQ2)
bit 2 = 1 RTC underflow (IRQ2)
bit 1 = 1 display cursor interrupt (IRQ2)
bit 0 = 1 low power interrupt (NMI)
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-1Eh R/W System Control Register
bits 7-6 speaker volume
= 00 off (0V)
= 01 soft (3V)
= 10 medium (5V)
= 11 loud (8V)
bits 5-4 crystal speed selection
= 00 10.738636 MHz
= 01 15.836773 MHz
= 10 21.477272 MHz
= 11 31.673550 MHz
bit 3 unused
bit 2 = 1 display on
bit 1 = 1 unit has been in backup mode
bit 0 = 1 CPU shutdown (set only)
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-1Fh R/W System Status Register
bit 7 = 0 A reset has occurred. This bit will be cleared by a system
reset; it is initialized to a one by the warmstart code.
bit 6 unused
bit 5 unused
bit 4 = 1 Internal 8254, 8259, or 8255 has been accessed.
bit 3 = 1 External /IO device has been accessed.
bit 2 = 1 PC-compatible MDA/CGA register has been accessed
bit 1 = 1 video RAM has been accessed
bit 0 = 1 UART has been accessed
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