R01UH0822EJ0100 Rev.1.00
Page 157 of 1041
Jul 31, 2019
RX13T Group
10. Clock Frequency Accuracy Measurement Circuit (CAC)
Figure 10.1
CAC Block Diagram
shows the pin configuration of the CAC.
Table 10.2
Pin Configuration of CAC
Pin Name
I/O
Function
CACREF
Input
Measurement reference clock input pin
Measurement
target clock
select circuit
Measurement
reference
clock select
circuit
F
requen
cy
div
iding
cir
cuit
F
re
q
ue
nc
y
di
vi
di
ng
ci
rcui
t
IWDTCLK
LOCO clock
HOCO clock
Main clock
1/4
1/8
1/32
16-bit counter
Comparator
CAULVR
1/128
1/1024
1/8192
Edge detection
circuit
CACREF
CACREFE
RSCS[2:0]
RCDS[1:0]
FMCS[2:0]
TCSS[1:0]
EDGES[1:0]
CFME
Count source
clock
Valid edge signal
Frequency error interrupt
request
Internal peripheral bus
RPS
1/32
CACNTBR
CALLVR
Measurement end interrupt
request
Overflow interrupt request
CAICR
CASTR
Interrupt control
circuit
Digital filter
DFS[1:0]
Measurement
target clock
DFS[1:0]
PCLKB
CFME: Bit in CACR0
CACREFE, FMCS[2:0], TCSS[1:0], EDGES[1:0]: Bits in CACR1
RPS, RSCS[2:0], RCDS[1:0], DFS[1:0]: Bits in CACR2
CAICR: CAC interrupt control register
CASTR: CAC status register
CAULVR: CAC upper-limit value setting register
CALLVR: CAC lower-limit value setting register
CACNTBR: CAC counter buffer register