Package Description
Table 67. MPC8548E Pinout Listing (continued)
Power
Notes
Signal
Package Pin Number
Pin Type
Supply
Analog Signals
MVREF
A18
I
MVREF
—
Reference
voltage signal
for DDR
SD_IMP_CAL_RX
SD_IMP_CAL_TX
SD_PLL_TPA
L28
AB26
U26
I
200Ω to
—
—
24
GND
I
100Ω to
GND
O
—
Notes:
1. All multiplexed signals are listed only once and do not re-occur. For example, LCS5/DMA_REQ2 is listed only once in the
local bus controller section, and is not mentioned in the DMA section even though the pin also functions as DMA_REQ2.
2. Recommend a weak pull-up resistor (2–10 kΩ) be placed on this pin to OV
3. A valid clock must be provided at POR if TSEC4_TXD[2] is set = 1.
4. This pin is an open drain signal.
.
DD
5. This pin is a reset configuration pin. It has a weak internal pull-up P-FET which is enabled only when the processor is in the
reset state. This pull-up is designed such that it can be overpowered by an external 4.7-kΩ pull-down resistor. However, if the
signal is intended to be high after reset, and if there is any device on the net which might pull down the value of the net at
reset, then a pullup or active driver is needed.
6. Treat these pins as no connects (NC) unless using debug address functionality.
7. The value of LA[28:31] during reset sets the CCB clock to SYSCLK PLL ratio. These pins require 4.7-kΩ pull-up or pull-down
resistors. See Section 19.2, “CCB/SYSCLK PLL Ratio.”
8. The value of LALE, LGPL2, and LBCTL at reset set the e500 core clock to CCB clock PLL ratio. These pins require 4.7-kΩ
pull-up or pull-down resistors. See the Section 19.3, “e500 Core PLL Ratio.”
9. Functionally, this pin is an output, but structurally it is an I/O because it either samples configuration input during reset or
because it has other manufacturing test functions. This pin will therefore be described as an I/O for boundary scan.
10.This pin functionally requires a pull-up resistor, but during reset it is a configuration input that controls 32- vs. 64-bit PCI
operation. Therefore, it must be actively driven low during reset by reset logic if the device is to be configured to be a 64-bit
PCI device. Refer to the PCI Specification.
11.This output is actively driven during reset rather than being three-stated during reset.
12.These JTAG pins have weak internal pull-up P-FETs that are always enabled.
13.These pins are connected to the V /GND planes internally and may be used by the core power supply to improve tracking
DD
and regulation.
14.Internal thermally sensitive resistor.
15.No connections should be made to these pins if they are not used.
16.These pins are not connected for any use.
17.PCI specifications recommend that a weak pull-up resistor (2–10 kΩ) be placed on the higher order pins to OV when using
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64-bit buffer mode (pins PCI_AD[63:32] and PCI1_C_BE[7:4]).
19.If this pin is connected to a device that pulls down during reset, an external pull-up is required to drive this pin to a safe state
during reset.
20.This pin is only an output in FIFO mode when used as Rx flow control.
24.Do not connect.
MPC8548E PowerQUICC™ III Integrated Processor Hardware Specifications, Rev. 6
Freescale Semiconductor
97
FREESCALE [ Freescale ]
