9. Resets, Clocks and Power-up Options
175
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
9.3.2
Configuration Slave Mode
When there is a 60x bus device with the capability to be a configuration master in a PowerSpan II
system (for example the PowerQUICC II) the Configuration Slave mode overrides the default
power-up option
—
the Multiplexed System Pins mode. The slave mode’s power-up options overwrite
the multiplex system pin mode power-up options that were sampled at PO_RST_ (see
When the PowerQUICC II is the configuration master, it asserts one of the A[0:6] signals when the
HRESET_ signal is low. Refer to the
MPC8260 (PowerQUICC II) User Manual
for a detailed
description of configuration master functionality.
PowerSpan II acts as a configuration slave under the following conditions:
•
PB_RSTCONF_ is connected to one of the configuration master’s A[0:6] lines
•
PB_RST_ is connected to the configuration master HRESET_ signal
•
PB_D is connected to the processor bus data line
The configuration slave power-up options are configured by PB_D as defined in
. PowerSpan
II configuration slave mode timing is illustrated in
Figure 23: PowerSpan II Configuration Slave Mode Timing
The configuration master updates all configuration slaves for each HRESET_ sequence. PowerSpan II
updates its the same configuration word accordingly after each sequence.
9.3.3
Assertion of P1_REQ64#
When PowerSpan II is used as the Central Resource in the system and controls both P1_REQ64# and
P1_RST#, the PWRUP_P1_REQ64_EN bit must be set to 1 in the
“Reset Control and Status Register”
. However, PowerSpan II does not assert P1_REQ64# signal until its configuration word is
latched. In order to meet this requirement, PowerSpan II must not be the last four configuration slaves
(PowerQUICC II can support up to seven external configuration slaves). By meeting these
requirements, PowerSpan II ensures that the timing parameters for a 64-bit data width are satisfied.
Power-up Options Configured
PB_D[0:7]
Configuration Word
PB_RSTCONF_
PB_RST_