
2-10
AC Timings
2.7.2.3 Host Reset Configuration
Host reset configuration allows the host to program the reset configuration word via the Host port after
PORESET
is deasserted, as described in the MSC8101 Reference Manual. The MSC8101 samples the
signals described in Table 2-12 one the rising edge of
PORESET
when the signal is deasserted.
If HPE is sampled high, the host port is enabled. In this mode the
RSTCONF
pin must be pulled up. The
device extends the internal
PORESET
until the host programs the reset configuration word register. The
host must write four 8-bit half-words to the Host Reset Configuration Register address to program the
reset configuration word, which is 32 bits wide. For more information, see the MSC8101 Reference
Manual. The reset configuration word is programmed before the internal PLL and DLL in the MSC8101
are locked. The host must program it after the rising edge of the
PORESET
input. In this mode, the host
must have its own clock that does not depend on the MSC8101 clock. After the PLL and DLL are locked,
HRESET
remains asserted for another 512 bus clocks and is then released. The
SRESET
is released three
bus clocks later (see Figure 2-3).
2.7.2.4 Hardware Reset Configuration
Hardware reset configuration is enabled if HPE is sampled low at the rising edge of
PORESET
. The value
driven on
RSTCONF
while
PORESET
changes from assertion to deassertion determines the MSC8101
configuration. If
RSTCONF
is deasserted (driven high) while
PORESET
changes, the MSC8101 acts as a
configuration slave. If
RSTCONF
is asserted (driven low) while
PORESET
changes, the MSC8101 acts
as a configuration master. Section 2.7.2.4, Hardware Reset Configuration, explains the configuration
sequence and the terms “configuration master” and “configuration slave.”
Directly after the deassertion of
PORESET
and choice of the reset operation mode as configuration
master or configuration slave, the MSC8101 starts the configuration process. The MSC8101 asserts
HRESET
and
SRESET
throughout the power-on reset process, including configuration. Configuration
takes 1024
CLOCKIN
cycles, after which
MODCK[1–3]
are sampled to determine the MSC8101’s working
mode.
Figure 2-3. Host Reset Configuration Timing
PORESET
Internal
HRESET
Input
Output (I/O)
SRESET
Output (I/O)
HRESET/SRESET are
extended for 512/515 BUS
clocks, respectively, from PLL
and DLL lock
PLL locks after
800 SPLLMFCLKs and
DLL locks 3073 BUS clocks
after PLL is locked.
When DLL is disabled,
reset period is shortened by
DLL lock time.
RSTCONF, HPE
pins are sampled
HRM, BTM
Any time
Host programs
Word
MODCK_H bits
are ready for PLL.
MODCK[1–3] pins
are sampled.
PORESET
Reset Configuration
1
2
3
5
4
6
asserted for
min 16
CLKIN.
PLL locked
DLL locked