M16C User Manual.pdf

External BusesMitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTER________(2) RDY function usage________To use the RDY function, set a software wait.________________The RDY function operates when the BCLK signal falls with the RDY pin at “L”; the bus does not varyfor 1 BCLK, and the state at that moment is held.________________The RDY function holds the state of bus for the period in which the RDY pin is at “L”, and releases it________________when the BCLK signal falls with the RDY pin at “H”. Figure 5.5.6 shows an example of RDY circuitthat holds the state of bus for 1 BCLK.BCLKSSCK1QCK2QRDYD1QD2QRRCS0RD• Timings in separate busBCLKCS0RD1Q2QRDY(1) (2) (1) (2)• Timings in multiplex busBCLKCS0RD1Q2QRDY(1) (2)(1) (2)(1) RDY accepted(2) RDY clearedThe state of data bus and that of address bus are held for the period between (1) and (2).________Figure 5.5.6. Example of RDY circuit holding state of bus for 1 BCLK537