
____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
36 of 366
PIN DESCRIPTION
present on the
TDMn_RX pin. This pulse must be repeated every N*125
s where
N is a positive integer (example: if N=16, it pulses every 2ms).
In one-clock mode, this signal is ignored and
TDMn_TX_SYNC specifies frame
alignment for both the transmit and receive interfaces of the TDMoP engine.
This pin is only active in external mode
(GCR1.MODE=1).
TDMn_RSIG_RTS
Ipu
TDMoP Receive Signaling Input
When the interface type is configured for E1 or T1, the transmit signaling function
of this pin is active.
In two-clock mode, this signal is clocked by
TDMn_RCLK.In one-clock mode, this signal, is clocked by
TDMn_TCLK.TDMoP Request To Send Input
When the interface type is configured for serial, the request-to-send function of this
pin is active. In this mode, the real-time status of this pin can be read from
This pin is only active in external mode
(GCR1.MODE=1).
Table 9-6. SDRAM Interface Pins
PIN DESCRIPTION
SD_CLK
O
8mA
SDRAM Clock
All SDRAM interface pins are updated or latched on the rising edge of SD_CLK.
SD_D[31:0]
IO
8mA
SDRAM Data
MSB is SD_D[31].
SD_DQM[3:0]
O
8mA
SDRAM Byte Enable Mask
SD_DQM[0] is associated with the least significant byte. SD_DQM[3] is associated
with the most significant byte. When a SD_DQM pin is high during a write cycle,
the associated byte is not written to SDRAM. When a SD_DQM pin is high during
a read cycle, the associated byte is not driven out of the SDRAM (the
SD_D pins
remain high-Z).
SD_A[11:0]
O
8mA
SDRAM Address Bus
MSB is SD_A[11].
SD_BA[1:0]
O
8mA
SDRAM Bank Select Outputs
The external SDRAMs used by the device have their memory organized into four
banks. These pins specify the bank to be accessed. The bank must be specified
SD_CS_N
O
8mA
SDRAM Chip Select (Active Low)
Driven low by the device to initiate a memory access (read or write) to the external
SDRAM.
SD_WE_N
O
8mA
SDRAM Write Enable (Active Low)
Driven low by the device when data is to be written to the external SDRAM. Left
high when data is to be read from the external SDRAM.
SD_RAS_N
O
8mA
SDRAM Row Address Strobe (Active Low)
Driven low by the device during SD_CLK cycles in which
SD_A[11:0] indicates the
SDRAM row address.
SD_CAS_N
O
8mA
SDRAM Column Address Strobe (Active Low)
Driven low by the device during SD_CLK cycles in which
SD_A[11:0] indicates the
SDRAM column address.