Note 1: nRI and the UART interrupts are active when PWRGD is active and the UARTS are either fully powered or in
AUTOPOWER DOWN mode.
Note 2: Active (push-pull) output drivers are required on these pins in the enhanced parallel port modes.
Note 3: An external pull-up must be provided for IOCHRDY.
Note 4: The pull-down on this pin is always active including when the output driver is tristated and regardless of the
state of PWRGD.
2.2 Buffer Type Summary
Table 2 below describes the buffer types shown in Table 1. All values are specified at Vcc = +3.3v, ±10%
Table 2 - SP37E760 3.3V Buffer Type Summary
BUFFER
DESCRIPTION
TYPE
IO12
O12
O12PD
OD12
O6
Input/Output. 12mA sink; 6mA source
Output. 12mA sink; 6mA source
Output. 12mA sink; 6mA source with 30µa pull-down
Open Drain. 12mA sink
Output. 6mA sink; 3mA source
OD14
OP14
IOP14
O4
Open Drain. 14mA sink
Output. 14mA sink; 14mA source. Backdrive Protected
Input/Output. 14mA sink; 14mA source. Backdrive Protected
Output. 4mA sink; 2mA source
ICLK
I
Input to Crystal Oscillator Circuit (TTL levels)
Input TTL Compatible
IS
Input with Schmitt Trigger
2.3 Output Drivers
Active output drivers in the SP37E760 will always achieve the minimum specified DC Electrical Characteristics shown
in Table 54. Note: If there is a pull-up on an external node driven by an active output driver the SP37E760 will sink
current from the pull-up through the low impedance source.
SMSC DS – SP37E760
Page 12
Rev. 04/13/2001
SMSC [ SMSC CORPORATION ]
