MC68HC901 Datasheet, PDF (59/73 Pages) Motorola, Inc – Multi-Function Peripheral

Electrical Characteristics
NUM
CHARACTERISTIC
MIN
MAX
UNIT
28 Receiver Ready (RR) Delay from Rising RC
—
600
ns
29 Transmitter Ready (TR) Delay from Rising TC
—
600
ns
30 TxO (A or B) Low from Rising Edge of CS or DS (Reset Time)
—
450
ns
31^{3 Timer Output (TxO) Valid from Falling t}clk ^{that Causes Timeout}
—
2 t_clk + 300
ns
32 Timer Clock (t_clk) Low Time
33 Timer Clock (t_clk) High Time
34 Timer Clock (t_clk) Cycle Time
35 RESET Low Time
110
—
ns
110
—
ns
250
1000
ns
2
—
µs
36 Delay to Falling IRQ from Ix Active Transition
—
380
ns
37 Transmitter Interrupt Delay from Falling Edge of TC
—
550
ns
38 Receiver Interrupt Delay from Rising Edge of RC (Buffer Full)
—
800
ns
39 Receiver Interrupt Delay from Falling Edge of RC (Error)
—
800
ns
40 SI Setup Time from Rising Edge of RC (Divide by 1 Only)
80
—
ns
41 SI Hold Time from Rising Edge of RC (Divide by 1 Only)
350
—
ns
42 SO Data Valid from Falling Edge of TC (Divide by 1 Only)
—
440
ns
43 TC Low Time
500
—
ns
44 TC High Time
500
—
ns
45 TC Cycle Time
1.05
∞
µs
46 RC Low Time
500
—
ns
47 RC High Time
500
—
ns
48 RC Cycle Time
1.05
∞
µs
49^{3 CS, IACK, DS Width Low}
—
80
t_cyc
50 SO Data Valid from Falling Edge of TC (Divide by 16 Only)
—
490
ns
NOTES: 1.
2.
3.
4.
5.
If the setup time is not met, CS will not be recognized until the next falling clock.
If this setup time is met (for consecutive cycles), the minimum hold-off time of one clock cycle will be
obtained. If not met, the hold-off time will be two clock cycles.
t_cyc refers to the clock signal applied to the MFP CLK input pin. t_clk refers to the timer clock signal,
regardless of whether that signal comes from the XTAL1/XTAL2 crystal clock inputs or the TAI or TBI timer
inputs.
CS is latched internally, therefore if specifications 1 and 24 are met, then CS may be negated before the
falling clock and still initiate a bus cycle.
Although CS and DTACK are synchronized with the clock, the data out during a read cycle is
asynchronous to the clock, relying only on CS for timing.
8-6
MC68HC901 USER’S MANUAL
MOTOROLA