SLLS890C August 2008 – April 2024 TL28L92
PRODUCTION DATA
The output ports are controlled from six places: the OPCR, OPR, MR, Command, SOPR and ROPR registers. The OPCR register controls the source of the data for the output ports OP2 through OP7. The data source for output ports OP0 and OP1 is controlled by the MR and CR registers. When the OPR is the source of the data for the output ports, the data at the ports is inverted from that in the OPR register. The content of the OPR register is controlled by the set output port bits command and the reset output bits command. These commands are at 0xE and 0xF, respectively. When these commands are used, action takes place only at the bit locations where ones exist. For example, a one in bit location 5 of the data word used with the set output port bits command will result in OPR5 being set to one. The OP5 would then be set to zero (VSS). Similarly, a one in bit position 5 of the data word associated with the reset output ports bits command would set OPR5 to zero and, hence, the pin OP5 to a one (VDD).
These pins along with the IP pins and their change-of-state detectors are often used for modem and DMA control.