h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 482

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 14 Controller Area Network (HCAN)
14.3.16 Unread Message Status Register (UMSR)
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.
Note:
14.3.17 Local Acceptance Filter Masks (LAFML, LAFMH)
LAFML and LAFMH are 16-bit registers that individually set the identifier bits of the message to
be stored in mailbox 0 as Don't Care. For details, see section 14.4.4, Message Reception. The
relationship between the identifier bits and mask bits are shown in the following.
Rev. 2.00 Dec. 05, 2005 Page 444 of 724
REJ09B0200-0200
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Bit Name
UMSR7
UMSR6
UMSR5
UMSR4
UMSR3
UMSR2
UMSR1
UMSR0
UMSR15
UMSR14
UMSR13
UMSR12
UMSR11
UMSR10
UMSR9
UMSR8
*
Only 1 can be written to clear the flag.
Initial
Value
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
R/W
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
R/(W)*
Description
Each bit indicates that the received message has been
overwritten by a new message before being read.
[Setting condition]
•
[Clearing condition]
•
When a new message is received before RXPR is
cleared
Writing 1