Micro Crystal
Ultra Small Real-Time Clock Module with SPI-Bus Interface
RV-8063-C7
October 2018
46/58
Rev. 1.1
SPI-BUS CHARACTERISTICS
6.4.
V
DD
= 1.8 V to 5.5 V; V
SS
= 0 V; T
A
= -40°C to +85°C; f
OSC
= 32.768 kHz; unless otherwise specified. All timing
values are valid within the operating supply voltage and temperature range and referenced to V
IL
and V
IH
with an
input voltage swing of V
SS
to V
DD
.
SPI-bus timing:
R/W
RA0
b6
b0
b0
b0
b6
b7
SDI
SDO
SDO
Hi Z
Hi Z
SDI
SCL
CE
WRITE
READ
tw(CE)
80%
20%
tclk(L)
tf
th(CE)
trec(CE)
tdis(SDO)
td(R)SDO
tt(SDI-SDO)
tr
th
tsu
tclk(H)
tSCL
tsu(CE)
b7
SA2
b6
b7
≈
≈
≈
≈
≈
≈
≈
≈
≈
≈
≈
≈
≈
≈
SPI-bus parameters:
SYMBOL
PARAMETER
CONDITIONS
V
DD
= 1.8 V
to 3.0 V
V
DD
> 3.0 V
to 5.5 V
UNIT
MIN
MAX
MIN
MAX
f
SCL
SCL clock frequency
5
7
MHz
t
SCL
SCL time
200
140
ns
t
clk(H)
Clock HIGH time
80
80
ns
t
clk(L)
Clock LOW time
110
60
ns
t
r
Rise time
For SCL signal
100
100
ns
t
f
Fall time
For SCL signal
100
100
ns
t
su(CE)
CE set-up time
15
15
ns
t
h(CE)
CE hold time
10
10
ns
t
rec(CE)
CE recovery time
50
50
ns
t
w(CE)
CE pulse width
Measured after valid subaddress
is received
0.99
0.99
s
t
su
Set-up time
Set-up time for SDIO data
5
5
ns
t
h
Hold time
Hold time for SDIO data
50
20
ns
t
d(R)SDO
SDO read delay time
Bus load = 50 pF
110
60
ns
t
dis(SDO)
SDO disable time
No load value; bus will be held
up by bus capacitance; use RC
time constant with application
values
50
50
ns
t
t(SDI-SDO)
Transition time from SDI to SDO
To avoid bus conflict; on pin
SDIO
0
0
ns
