Unread Message Status Register (Umsr) - Renesas H8S Series Hardware Manual

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
15 UMSR7
14 UMSR6
13 UMSR5
12 UMSR4
11 UMSR3
10 UMSR2
9 UMSR1
8 UMSR0
7 UMSR15
6 UMSR14
5 UMSR13
4 UMSR12
3 UMSR11
2 UMSR10
1 UMSR9
0 UMSR8
Note: * Only 1 can be written to clear the flag.
Initial Value R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
0 R/W
R/(W) *
0
R/(W) *
0
R/(W) *
0
Section 15 Controller Area Network (HCAN)
Description
[Setting condition]
•
When a new message is received before
RXPR is cleared
[Clearing condition]
•
Writing 1
Rev. 6.00 Mar 15, 2006 page 407 of 570
REJ09B0211-0600