Rev. 1.20
65
October 28, 2020
BC45B4523
0
1
1
0
0
1
0
0
0
0
0
0
0
0
0
0
MOSI
SCK
NCS
Timer (0x02)
MISO
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Output data
Addr : 0x0C : Timer
Timer Value
Target Address (0x0C)
is recognized
0x04
0x03
0x02
0x01
0x00
0x05
0x06
0x07
Point Timer Value is Latched
The timer can be controlled by events listed below.
•
Manually start through setting the TStartNow bit (Sector0-0x09.1).
•
Manually stop through setting the TStopNow bit (Sector0-0x09.2).
• Automatically start when
♦
Transmission-beginning event occurs and the TStartTxBegin bit (Sector0-0x2B.0) is set.
♦
Transmission-end event occurs and the TStartTxEnd bit (Sector0-0x2B.1) is set.
• Automatically stop when
♦
Reception-beginning event occurs and the TStoptRxBegin bit (Sector0-0x2B.2) is set.
♦
Reception-end event occurs and the TStopRxEnd bit (Sector0-0x2B.3) is set.
The definitions of ending and beginning in the transmission and reception are described in the following table.
Event
Definition
Transmission-beginning
Start of frame of downlink telegram begins to be transmitted
Transmission-end
End of frame or last bit of downlink telegram is transmitted
Reception-beginning
1st valid bit from uplink is received
Reception-end
End of frame of uplink telegram is received or
Error occurs during receiving
Definitions of Beginning and End in the Transmission and Reception
Apart from using a time-out feature for no-card-response indicator, the timer can be used for programmable one-
shot or periodic trigger. The registers associated with the timer are summarized as follows.
Register
Address.Bit
Indication
Type
Default
Value
Trunning
Sector0-0x05.7
The timer is operating
Read Only
0
TimerIEn
Sector0-0x06.5
The timer interrupt enable
Read/Write
0
TimerIRq
Sector0-0x07.5
The timer interrupt request occurring if the timer value
reaches 0
Read/Write
0
TStopNow
Sector0-0x09.2
Stop the timer immediately
Write Only
0
TStartNow
Sector0-0x09.1
Start the timer immediately
Write Only
0
TimerValue
Sector0-0x0C
Display the current timer value
Read Only
0xFF
TAutoRestart Sector0-0x2A.5
Configure the timer to restart automatically after the
counter reaches zero.
The timer restarts from TReloadValue
Read/Write
0
TPreScaler
Sector0-0x2A.[4:0] Clock Prescaler for timer clock
Read/Write 00111
TStopRxEnd
Sector0-0x2B.3
Set to stop the timer automatically after RX EOF is found Read/Write
0
TStopRxBegin Sector0-0x2B.2
Set to stop the timer automatically after RX SOF is found Read/Write
1