MICROCHIP COM91C32P

The COM91C32 local area network transceiver (LANT) is an improved version of the COM90C32. It reduces both node cost and board real estate. The COM91C32 is a companion chip to either the COM9026 or COM90C26 local area network controller (LANC), the HYC9068 local area network driver (LAND), and the HYC9058 high impedance transceiver (HiT). The COM91C32 contains two circuits not available on the COM90C32. A 20MHz crystal oscillator has been built in to eliminate the need for an external oscillator. In addition, the external power on reset circuit required by the COM9026/COM90C26 has been integrated inside the COM91C32 to reduce the number of components, their related costs, and board real estate. The COM91C32 performs the functions necessary to allow simple interface to the transmission media for ARCNET local area networks. The COM91C32 produces two 5MHz clocks for the COM9026/COM90C26. The first one (LANCLK) is free running and feeds the clock input (pin 19) of the COM9026/COM90C26. The second one (CA) has start/stop capability controlled by the DsYNC output of the COM9026/COM90C26 as well as the data received from the network. During data reception, the COM91C32 will convert incoming serial received data from the HiT or LAND circuit to NRZ form which will directly feed the RX input of the COM9026/COM90C26 (pin 38). During transmission, the COM91C32 converts the transmit data from the COM9026/COM90C26 TX, (pin 37) into the waveforms necessary to drive the HYC9058 or HYC9068.

• Compatible with the COM9026 and COM90C26 LANC
• Compatible with the HYC9058 HiT
• Compatible with the HYC9068 LAND
• Functionally compatible with the COM90C32
• Reduces node chip count
• Built-in 20MHz crystal oscillator
• Internal Power On Reset for COM9026/COM90C26
• Provides all clocks for COM9026/COM90C26
• Low power CMOS technology
• TTL compatible
• 5V only power supply