mitsubishi - Al Kossow's Bitsavers

MIT~UBISHI MICROCOMPUTERSMS0740-XXXSPSINGLE-CHIP 8-BIT CMOS MICROCOMPUTER(4) Pulse width measurment mode (11 )The frequency, produced by dividing the oscillation frequencyby16, is counted only while the pin CNTR levelis low. When the counter contents reach to "0," the interruptrequest bit is set to "1," the timer latch contentsare re-Ioaded and the count is continued.Fig. 5 shows the relationship between the timer controlregister contents and the timer modes.Also shown are the processor mode and other bits.When reset or the STP instruction is executed, the timerX prescaler is set in FF 16 and the timer X latch is setin 01 16 . When the STP instruction is executed, the frequencyproduced by dividing the oscillation frequencyby 16 serves as the timer X prescaler input, regardlessof the timer X mode bit. This mode is released eitherwhen the timer X interrupt request bit is set to "1" orwhen resetting is accomplished and resume the modedetermined by the timer X mode bit. For details on theoperation of the STP instruction, reference should bemade to the section on the oscillator circuit.r I I /XII J I ILL Timer control register (FF 16 address)Processor mode bits00: Single chip mocle01: Memory expansion mode10: Microprocessor modE!1 1: Evaluation chip mode(forcibly established whenCNVss pin is set high)Timer X mode bits00: Timer mode01: Pulse output mode1 0: Event counter mode1 1: Pulse width measurment modeTimer X count stop bit0: Count start1: Count stopTimer X interrupt enable bit0: Interrupt disable1: Interrupt enableTimer X interrupt request bit0"': No inter~upt request1: Interrupt request presentflg.SConfiguration of timer control registerf (91)RESETRESEToUT __ ~ __________________ ~SYNCAddressData8 clock cycle-15 clock cycle:depends on internal state ofmicrocomputer when resettingis undertaken.Note 1Note 2Reset addressbrought from vector tableThe relationship between ¢ and f( 91) is normally f( 91) = 4, 'II,but when the address is the 110 expander address (00 16 -DF 16 ), it is f(