Data Timeout Register (Dtoutr) - Renesas H8S/2158 User Manual

Section 19 Multimedia Card Interface (MCIF)
Bit Bit Name
7 —
to
1
0 CTSEL0

19.3.11 Data Timeout Register (DTOUTR)

DTOUTR specifies the cycle to generate a data timeout. The 16-bit counter (DTOUTC) and a
prescaler, to which the CPU does not have access, count the system clock to monitor the data
timeout. The prescaler always counts the system clock, and outputs a count pulse for every 10000
system clocks. The DTOUTC starts counting the prescaler output from the start of the command
sequence. The DTOUTC is cleared when the command sequence has ended, or when the
command sequence has been aborted by setting the CMDOFF bit to 1, after which the DTOUTC
stops counting the prescaler output.
When the command sequence does not end, the DTOUTC continues counting the prescaler output,
and enters the data timeout error state when the number of prescaler outputs reaches the number
specified in DTOUTR. When the DTERIE bit in INTCR1 is set to 1, the DTERI flag in INTSTR1
is set. As the DTOUTC continues counting prescaler output, the DTERI flag setting condition is
repeatedly generated. To perform data timeout error handling, the command sequence should be
aborted by setting the CMDOFF bit to 1, and then the DTERI flag should be cleared to prevent
extra-interrupt generation.
For a command with data busy status, as the command sequence is terminated before entering the
data busy state, data timeout cannot be monitored. Timeout in the data busy state should be
monitored by firmware.
Bit Bit Name
15 —
to
0
Rev. 3.00 Jan 25, 2006 page 644 of 872
REJ09B0286-0300
Initial Value R/W
All 0 R
0 R/W
Initial Value R/W
All 1 R/W
Description
Reserved
These bits are always read as 0 and cannot be
modified.
Command Timeout Select Specifies the number
of transfer clocks from command transmission
completion to response reception completion.
0: 128 transfer clocks
1: 256 transfer clocks
Description
Data Timeout Time/10000
Data timeout time can be obtained by system
clock cycle × DTOUTR setting value × 10000.