HD6417750RF240V Datasheet, PDF (441/606 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 15 Controller Area Network (HCAN)
15.3.16 Unread Message Status Register (UMSR)
The unread message status register (UMSR) is a 16-bit register containing status flags that
indicate, for individual mailboxes (buffers), that a received message has been overwritten by a
new receive message before being read. When overwritten by a new message, data in the unread
receive message is lost.
Bit Bit Name Initial Value R/W
Description
15 UMSR7
0
14 UMSR6
0
13 UMSR5
0
12 UMSR4
0
11 UMSR3
0
10 UMSR2
0
R/W
[Setting condition]
R/W
• When a new message is received before
R/W
RXPR is cleared
R/W
[Clearing condition]
R/W
• Writing 1
R/W
9
UMSR1
0
8
UMSR0
0
7
UMSR15 0
6
UMSR14 0
5
UMSR13 0
4
UMSR12 0
3
UMSR11 0
2
UMSR10 0
1
UMSR9
0
0
UMSR8
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/(W)^*
R/(W)^*
R/(W)^*
Note: * Only 1 can be written to clear the flag.
Rev. 7.00 Sep. 11, 2009 Page 405 of 566
REJ09B0211-0700