upd70f3402 Renesas Electronics Corporation., upd70f3402 Datasheet - Page 613

• Manufacturer Part Number: upd70f3402
• Description: 32-/16-bit Single-chip Microcontroller With Can Interface
• Manufacturer: Renesas Electronics Corporation.

(17) CAN module transmit history list register (CnTGPT)
(a) Read
(b) Write
Note: The read value of TGPT0 to TGPT7 is invalid when THPM = 1.3.
Remark:
CnTGPT
CnTGPT
TGPT7 to TGPT0
The CnTGPT register is used to read the transmit history list.
THPM
Figure 16-40: CAN Module Transmit History List Register (CnTGPT) Format (1/2)
TOVF
0.....31
0
1
0
1
Transmission from message buffers 0 to 7 is not recorded to the transmit history list in the
normal operation mode with ABT.
Note 1
TGPT7 TGPT6 TGPT5 TGPT4 TGPT3 TGPT2 TGPT1 TGPT0
15
15
7
0
0
7
0
All the message buffer numbers that have not been read are preserved. All the numbers
of the message buffers to which a new data frame or remote frame has been transmitted
are recorded to the transmit history list (the transmit history list has a vacant element).
At least 7 entries have been stored since the host processor serviced the THL last time
(i.e. read CnTGPT). The first 6 entries are sequentially stored whereas the last entry
might have been overwritten by newly transmitted messages a number of times because
all buffer numbers are stored at position LOPT-1 when TOVF bit is set to 1. As a conse-
quence receptions cannot be completely recovered in the order that they were received
The transmit history list has at least one message buffer number that has not been read.
The transmit history list has no message buffer numbers that have not been read.
When the CnTGPT register is read, the contents of the element indexed by the read
pointer (TGPT) of the transmit history list are read. These contents indicate the
number of the message buffer to which a data frame or a remote frame was transmit-
ted last.
14
14
6
0
0
6
0
User’s Manual U16702EE3V2UD00
13
13
5
0
0
5
0
Chapter 16 FCAN Controller
12
12
4
0
0
4
0
Transmit history list overflow bit
Transmit history list read pointer
Transmit history pointer match
11
11
3
0
0
3
0
10
10
2
0
0
2
0
THPM
9
1
9
0
1
0
TOVF
TOVF
Clear
8
0
8
0
0
see Table
Address R/W After reset
Address R/W After reset
16-16
R/W
xx02H
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