RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 14 CAN CONTROLLER
(18) CAN module transmit history list register (C0TGPT, C1TGPT)
The C0TGPT, C1TGPT register is used to read the transmit history list.
(a) Read
(b) Write
(a) Read
Figure 14-44. Format of CAN Module Transmit History List Register (C0TGPT, C1TGPT) (1/2)
Address: F05F4H (C0TGPT), F03A4H (C1TGPT) After reset: xx02H R/W
C0TGPT,
C1TGPT
C0TGPT,
C1TGPT
15 14 13 12 11 10 9 8
TGPT7 TGPT6 TGPT5 TGPT4 TGPT3 TGPT2 TGPT1 TGPT0
7 6 5 4 3 2 1 0
0 0 0 0 0 0 THPM TOVF
15 14 13 12 11 10 9 8
0 0 0 0 0 0 0 0
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 Clear
TOVF
TGPT7-TGPT0 Transmit History List Read Pointer
0 to 15 When the C0TGPT, C1TGPT 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 transmitted
last.
THPM Note Transmit History Pointer Match
0 The transmit history list has at least one message buffer number that has not been read.
1 The transmit history list has no message buffer number that has not been read.
Note The read value of TGPT0 to TGPT7 is invalid when THPM = 1.
TOVF Transmit History List Overflow Bit
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).
1 At least 7 entries have been stored since the host processor has serviced the THL last
time (i.e. read C0TGPT, C1TGPT). The first 6 entries are sequentially stored while the
last entry can have been overwritten whenever a message is newly transmitted because
all buffer numbers are stored at position LOPT-1 when TOVF bit is set. Thus the
sequence of transmissions can not be recovered completely now.
Note If TOVF is set, THPM is no longer cleared on message transmission, but THPM is still set,
if all entries of CTGPT are read by software.
Remark Transmission from message buffer 0 to 7 is not recorded to the transmit history list in
the normal operation mode with ABT.
R01UH0317EJ0004 Rev. 0.04 869
Feb. 22, 2013