
CHAPTER 19 CAN CONTROLLER
Preliminary User’s Manual U17790EJ1V0UD
803
(15) CANn module receive history list register (CnRGPT)
The CnRGPT register is used to read the receive history list.
After reset: xx02H
R/W
Address: C0RGPT 03FEC060H, C1RGPT 03FEC660H
(a) Read
15
14
13
12
11
10
9
8
CnRGPT
RGPT7
RGPT6
RGPT5
RGPT4
RGPT3
RGPT2
RGPT1
RGPT0
7
6
5
4
3
2
1
0
RHPM
ROVF
(b) Write
15
14
13
12
11
10
9
8
CnRGPT
0
7
6
5
4
3
2
1
0
Clear
ROVF
(a) Read
RGPT7 to RGPT0
Receive history list read pointer
0 to 31
When the CnRGPT register is read, the contents of the element indexed by the receive history list
get pointer (RGPT) of the receive history list are read. These contents indicate the number of the
message buffer in which a data frame or a remote frame has been stored.
RHPM
Note
Receive history list pointer match
0
The receive history list has at least one message buffer number that has not been read.
1
The receive history list has no message buffer numbers that have not been read.
ROVF
Receive history list overflow bit
0
All the message buffer numbers that have not been read are preserved. All the numbers of the
message buffers in which a new data frame or remote frame has been received and stored are recorded
to the receive history list (the receive history list has a vacant element).
1
At least 23 entries have been stored since the host processor serviced the RHL last time (i.e. read
CnRGPT). The first 22 entries are sequentially stored whereas the last entry might have been
overwritten by newly received messages a number of times because all buffer numbers are stored at
position LIPT-1 when the ROVF bit is set to 1. As a consequence receptions cannot be completely
recovered in the order that they were received.
(b) Write
Clear ROVF
Setting of ROVF bit
0
ROVF bit is not changed.
1
ROVF bit is cleared to 0.
Note
The read value of the RGPT0 to RGPT7 bits is invalid when the RHPM bit = 1.